815072257 has 2 divisors, whose sum is σ = 815072258. Its totient is φ = 815072256.

The previous prime is 815072239. The next prime is 815072263. The reversal of 815072257 is 752270518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 594579456 + 220492801 = 24384^2 + 14849^2 .

It is a cyclic number.

It is not a de Polignac number, because 815072257 - 2⁷ = 815072129 is a prime.

It is equal to p_41881267 and since 815072257 and 41881267 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (815072207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407536128 + 407536129.

It is an arithmetic number, because the mean of its divisors is an integer number (407536129).

Almost surely, 2^815072257 is an apocalyptic number.

It is an amenable number.

815072257 is a deficient number, since it is larger than the sum of its proper divisors (1).

815072257 is an equidigital number, since it uses as much as digits as its factorization.

815072257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39200, while the sum is 37.

The square root of 815072257 is about 28549.4703453497. The cubic root of 815072257 is about 934.1114675598. Note that the first 3 decimals are identical.

The spelling of 815072257 in words is "eight hundred fifteen million, seventy-two thousand, two hundred fifty-seven".