256621535775365 has 32 divisors (see below), whose sum is σ = 311738979310080. Its totient is φ = 202777240320000.

The previous prime is 256621535775361. The next prime is 256621535775379. The reversal of 256621535775365 is 563577535126652.

It is not a de Polignac number, because 256621535775365 - 2² = 256621535775361 is a prime.

It is a super-2 number, since 2×256621535775365² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256621535775295 and 256621535775304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256621535775361) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 557413691 + ... + 557873879.

It is an arithmetic number, because the mean of its divisors is an integer number (9741843103440).

Almost surely, 2^{256621535775365} is an apocalyptic number.

It is an amenable number.

256621535775365 is a deficient number, since it is larger than the sum of its proper divisors (55117443534715).

256621535775365 is a wasteful number, since it uses less digits than its factorization.

256621535775365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462573.

The product of its digits is 1190700000, while the sum is 68.

The spelling of 256621535775365 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, five hundred thirty-five million, seven hundred seventy-five thousand, three hundred sixty-five".