256631075351461 has 4 divisors (see below), whose sum is σ = 264909497137024. Its totient is φ = 248352653565900.

The previous prime is 256631075351449. The next prime is 256631075351489. The reversal of 256631075351461 is 164153570136652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256631075351461 - 2⁵ = 256631075351429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256631075351401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4139210892735 + ... + 4139210892796.

It is an arithmetic number, because the mean of its divisors is an integer number (66227374284256).

Almost surely, 2^{256631075351461} is an apocalyptic number.

It is an amenable number.

256631075351461 is a deficient number, since it is larger than the sum of its proper divisors (8278421785563).

256631075351461 is an equidigital number, since it uses as much as digits as its factorization.

256631075351461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8278421785562.

The product of its (nonzero) digits is 13608000, while the sum is 55.

The spelling of 256631075351461 in words is "two hundred fifty-six trillion, six hundred thirty-one billion, seventy-five million, three hundred fifty-one thousand, four hundred sixty-one".