256507176052661 has 2 divisors, whose sum is σ = 256507176052662. Its totient is φ = 256507176052660.

The previous prime is 256507176052619. The next prime is 256507176052669. The reversal of 256507176052661 is 166250671705652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151809381999025 + 104697794053636 = 12321095^2 + 10232194^2 .

It is a cyclic number.

It is not a de Polignac number, because 256507176052661 - 2⁶ = 256507176052597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256507176052661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256507176052669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128253588026330 + 128253588026331.

It is an arithmetic number, because the mean of its divisors is an integer number (128253588026331).

Almost surely, 2^{256507176052661} is an apocalyptic number.

It is an amenable number.

256507176052661 is a deficient number, since it is larger than the sum of its proper divisors (1).

256507176052661 is an equidigital number, since it uses as much as digits as its factorization.

256507176052661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31752000, while the sum is 59.

The spelling of 256507176052661 in words is "two hundred fifty-six trillion, five hundred seven billion, one hundred seventy-six million, fifty-two thousand, six hundred sixty-one".