256500420267161 has 16 divisors (see below), whose sum is σ = 293351511674880. Its totient is φ = 219701379885840.

The previous prime is 256500420267151. The next prime is 256500420267181. The reversal of 256500420267161 is 161762024005652.

It is a cyclic number.

It is not a de Polignac number, because 256500420267161 - 2¹⁰ = 256500420266137 is a prime.

It is a super-2 number, since 2×256500420267161² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256500420267101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 443843966 + ... + 444421496.

It is an arithmetic number, because the mean of its divisors is an integer number (18334469479680).

Almost surely, 2^{256500420267161} is an apocalyptic number.

It is an amenable number.

256500420267161 is a deficient number, since it is larger than the sum of its proper divisors (36851091407719).

256500420267161 is a wasteful number, since it uses less digits than its factorization.

256500420267161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622484.

The product of its (nonzero) digits is 1209600, while the sum is 47.

The spelling of 256500420267161 in words is "two hundred fifty-six trillion, five hundred billion, four hundred twenty million, two hundred sixty-seven thousand, one hundred sixty-one".