256623313660665 has 16 divisors (see below), whose sum is σ = 469254059265408. Its totient is φ = 117313514816256.

The previous prime is 256623313660657. The next prime is 256623313660699. The reversal of 256623313660665 is 566066313326652.

It is a happy number.

It is not a de Polignac number, because 256623313660665 - 2³ = 256623313660657 is a prime.

It is a super-2 number, since 2×256623313660665² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256623313660599 and 256623313660608.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1222015779232 + ... + 1222015779441.

It is an arithmetic number, because the mean of its divisors is an integer number (29328378704088).

Almost surely, 2^{256623313660665} is an apocalyptic number.

It is an amenable number.

256623313660665 is a deficient number, since it is larger than the sum of its proper divisors (212630745604743).

256623313660665 is a wasteful number, since it uses less digits than its factorization.

256623313660665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2444031558688.

The product of its (nonzero) digits is 125971200, while the sum is 60.

The spelling of 256623313660665 in words is "two hundred fifty-six trillion, six hundred twenty-three billion, three hundred thirteen million, six hundred sixty thousand, six hundred sixty-five".