256507724562457 has 2 divisors, whose sum is σ = 256507724562458. Its totient is φ = 256507724562456.

The previous prime is 256507724562443. The next prime is 256507724562487. The reversal of 256507724562457 is 754265427705652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 172446167279376 + 84061557283081 = 13131876^2 + 9168509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256507724562457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256507724562392 and 256507724562401.

It is not a weakly prime, because it can be changed into another prime (256507724562487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128253862281228 + 128253862281229.

It is an arithmetic number, because the mean of its divisors is an integer number (128253862281229).

Almost surely, 2^{256507724562457} is an apocalyptic number.

It is an amenable number.

256507724562457 is a deficient number, since it is larger than the sum of its proper divisors (1).

256507724562457 is an equidigital number, since it uses as much as digits as its factorization.

256507724562457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987840000, while the sum is 67.

The spelling of 256507724562457 in words is "two hundred fifty-six trillion, five hundred seven billion, seven hundred twenty-four million, five hundred sixty-two thousand, four hundred fifty-seven".