13815257 has 2 divisors, whose sum is σ = 13815258. Its totient is φ = 13815256.

The previous prime is 13815253. The next prime is 13815289. The reversal of 13815257 is 75251831.

It is an a-pointer prime, because the next prime (13815289) can be obtained adding 13815257 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12187081 + 1628176 = 3491^2 + 1276^2 .

It is a cyclic number.

It is not a de Polignac number, because 13815257 - 2² = 13815253 is a prime.

It is a super-2 number, since 2×13815257² = 381722651952098, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13815253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6907628 + 6907629.

It is an arithmetic number, because the mean of its divisors is an integer number (6907629).

Almost surely, 2^13815257 is an apocalyptic number.

It is an amenable number.

13815257 is a deficient number, since it is larger than the sum of its proper divisors (1).

13815257 is an equidigital number, since it uses as much as digits as its factorization.

13815257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 32.

The square root of 13815257 is about 3716.8880801014. Note that the first 3 decimals coincide. The cubic root of 13815257 is about 239.9493932649.

The spelling of 13815257 in words is "thirteen million, eight hundred fifteen thousand, two hundred fifty-seven".