256607514661 has 2 divisors, whose sum is σ = 256607514662. Its totient is φ = 256607514660.

The previous prime is 256607514613. The next prime is 256607514677. The reversal of 256607514661 is 166415706652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229738076100 + 26869438561 = 479310^2 + 163919^2 .

It is a cyclic number.

It is not a de Polignac number, because 256607514661 - 2⁷ = 256607514533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256607514601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128303757330 + 128303757331.

It is an arithmetic number, because the mean of its divisors is an integer number (128303757331).

Almost surely, 2^256607514661 is an apocalyptic number.

It is an amenable number.

256607514661 is a deficient number, since it is larger than the sum of its proper divisors (1).

256607514661 is an equidigital number, since it uses as much as digits as its factorization.

256607514661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1814400, while the sum is 49.

The spelling of 256607514661 in words is "two hundred fifty-six billion, six hundred seven million, five hundred fourteen thousand, six hundred sixty-one".