256124643869 has 4 divisors (see below), whose sum is σ = 256633838496. Its totient is φ = 255615449244.

The previous prime is 256124643811. The next prime is 256124643911. The reversal of 256124643869 is 968346421652.

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 a cyclic number.

It is not a de Polignac number, because 256124643869 - 2⁸ = 256124643613 is a prime.

It is a super-2 number, since 2×256124643869² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256124643169) 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, 254596559 + ... + 254597564.

It is an arithmetic number, because the mean of its divisors is an integer number (64158459624).

Almost surely, 2^256124643869 is an apocalyptic number.

It is an amenable number.

256124643869 is a deficient number, since it is larger than the sum of its proper divisors (509194627).

256124643869 is an equidigital number, since it uses as much as digits as its factorization.

256124643869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509194626.

The product of its digits is 14929920, while the sum is 56.

The spelling of 256124643869 in words is "two hundred fifty-six billion, one hundred twenty-four million, six hundred forty-three thousand, eight hundred sixty-nine".