Happy primes up to 8000

Happy primes: Primes that eventually reach 1 under iteration of: x -> sum of squares of digits of x.

There is 174 happy primes smaller than 8000.

Checkout happy primes up to: 100, 500, 1000, 10000.

7, 13, 19, 23, 31, 79, 97, 103, 109, 139, 167, 193, 239, 263, 293, 313, 331, 367, 379, 383, 397, 409, 487, 563, 617, 653, 673, 683, 709, 739, 761, 863, 881, 907, 937, 1009, 1033, 1039, 1093, 1151, 1277, 1303, 1373, 1427, 1447, 1481, 1487, 1511, 1607, 1663, 1697, 1733, 1847, 1933, 2003, 2039, 2063, 2111, 2221, 2309, 2333, 2339, 2383, 2393, 2417, 2557, 2693, 2741, 2833, 2851, 2903, 2963, 3001, 3019, 3067, 3079, 3083, 3109, 3137, 3209, 3301, 3313, 3319, 3323, 3329, 3331, 3371, 3391, 3463, 3607, 3637, 3643, 3673, 3709, 3779, 3797, 3803, 3823, 3833, 3907, 3923, 3931, 4111, 4127, 4157, 4217, 4271, 4363, 4441, 4447, 4481, 4517, 4663, 4721, 4751, 4817, 4871, 5147, 5227, 5281, 5417, 5471, 5477, 5527, 5569, 5659, 5741, 5821, 5879, 5897, 5987, 6037, 6053, 6073, 6163, 6197, 6203, 6329, 6337, 6343, 6353, 6361, 6367, 6373, 6389, 6637, 6661, 6673, 6701, 6703, 6719, 6733, 6763, 6791, 6803, 6899, 6917, 6971, 6983, 7039, 7127, 7309, 7331, 7451, 7457, 7481, 7541, 7547, 7589, 7603, 7691, 7793, 7841, 7937

• Learn more about Happy primes.
• All happy primes