255616521 has 4 divisors (see below), whose sum is σ = 340822032. Its totient is φ = 170411012.

The previous prime is 255616513. The next prime is 255616523. The reversal of 255616521 is 125616552.

255616521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 255616521 - 2³ = 255616513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (255616523) 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, 42602751 + ... + 42602756.

It is an arithmetic number, because the mean of its divisors is an integer number (85205508).

Almost surely, 2^255616521 is an apocalyptic number.

It is an amenable number.

255616521 is a deficient number, since it is larger than the sum of its proper divisors (85205511).

255616521 is an equidigital number, since it uses as much as digits as its factorization.

255616521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85205510.

The product of its digits is 18000, while the sum is 33.

The square root of 255616521 is about 15988.0117900882. The cubic root of 255616521 is about 634.6432128832.

The spelling of 255616521 in words is "two hundred fifty-five million, six hundred sixteen thousand, five hundred twenty-one".