256799665655 has 16 divisors (see below), whose sum is σ = 331875550944. Its totient is φ = 189630180480.

The previous prime is 256799665649. The next prime is 256799665657. The reversal of 256799665655 is 556566997652.

It is not a de Polignac number, because 256799665655 - 2¹⁶ = 256799600119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256799665657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2723357 + ... + 2816073.

It is an arithmetic number, because the mean of its divisors is an integer number (20742221934).

Almost surely, 2^256799665655 is an apocalyptic number.

256799665655 is a deficient number, since it is larger than the sum of its proper divisors (75075885289).

256799665655 is a wasteful number, since it uses less digits than its factorization.

256799665655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135346.

The product of its digits is 918540000, while the sum is 71.

The spelling of 256799665655 in words is "two hundred fifty-six billion, seven hundred ninety-nine million, six hundred sixty-five thousand, six hundred fifty-five".