256156437801 has 64 divisors (see below), whose sum is σ = 422311449600. Its totient is φ = 136077465600.

The previous prime is 256156437799. The next prime is 256156437809. The reversal of 256156437801 is 108734651652.

It is not a de Polignac number, because 256156437801 - 2¹ = 256156437799 is a prime.

It is a super-2 number, since 2×256156437801² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256156437809) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 425221 + ... + 832541.

It is an arithmetic number, because the mean of its divisors is an integer number (6598616400).

Almost surely, 2^256156437801 is an apocalyptic number.

It is an amenable number.

256156437801 is a deficient number, since it is larger than the sum of its proper divisors (166155011799).

256156437801 is a wasteful number, since it uses less digits than its factorization.

256156437801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407430.

The product of its (nonzero) digits is 1209600, while the sum is 48.

The spelling of 256156437801 in words is "two hundred fifty-six billion, one hundred fifty-six million, four hundred thirty-seven thousand, eight hundred one".