256665260633 has 4 divisors (see below), whose sum is σ = 257404930320. Its totient is φ = 255925590948.

The previous prime is 256665260627. The next prime is 256665260639. The reversal of 256665260633 is 336062566652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (256665260627) and next prime (256665260639).

It is a cyclic number.

It is not a de Polignac number, because 256665260633 - 2⁴ = 256665260617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256665260639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 369834323 + ... + 369835016.

It is an arithmetic number, because the mean of its divisors is an integer number (64351232580).

Almost surely, 2^256665260633 is an apocalyptic number.

It is an amenable number.

256665260633 is a deficient number, since it is larger than the sum of its proper divisors (739669687).

256665260633 is an equidigital number, since it uses as much as digits as its factorization.

256665260633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739669686.

The product of its (nonzero) digits is 6998400, while the sum is 50.

The spelling of 256665260633 in words is "two hundred fifty-six billion, six hundred sixty-five million, two hundred sixty thousand, six hundred thirty-three".