256631443553 has 4 divisors (see below), whose sum is σ = 264909877248. Its totient is φ = 248353009860.

The previous prime is 256631443511. The next prime is 256631443561. The reversal of 256631443553 is 355344136652.

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 256631443553 - 2⁶ = 256631443489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256631443498 and 256631443507.

It is not an unprimeable number, because it can be changed into a prime (256631443583) 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, 4139216801 + ... + 4139216862.

It is an arithmetic number, because the mean of its divisors is an integer number (66227469312).

Almost surely, 2^256631443553 is an apocalyptic number.

It is an amenable number.

256631443553 is a deficient number, since it is larger than the sum of its proper divisors (8278433695).

256631443553 is an equidigital number, since it uses as much as digits as its factorization.

256631443553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8278433694.

The product of its digits is 3888000, while the sum is 47.

The spelling of 256631443553 in words is "two hundred fifty-six billion, six hundred thirty-one million, four hundred forty-three thousand, five hundred fifty-three".