256621007344731 has 8 divisors (see below), whose sum is σ = 343195063197504. Its totient is φ = 170563811527560.

The previous prime is 256621007344711. The next prime is 256621007344739. The reversal of 256621007344731 is 137443700126652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256621007344731 - 2¹³ = 256621007336539 is a prime.

It is a super-2 number, since 2×256621007344731² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256621007344739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129215007741 + ... + 129215009726.

It is an arithmetic number, because the mean of its divisors is an integer number (42899382899688).

Almost surely, 2^{256621007344731} is an apocalyptic number.

256621007344731 is a deficient number, since it is larger than the sum of its proper divisors (86574055852773).

256621007344731 is a wasteful number, since it uses less digits than its factorization.

256621007344731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258430017801.

The product of its (nonzero) digits is 5080320, while the sum is 51.

The spelling of 256621007344731 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, seven million, three hundred forty-four thousand, seven hundred thirty-one".