255616391 has 2 divisors, whose sum is σ = 255616392. Its totient is φ = 255616390.

The previous prime is 255616363. The next prime is 255616399. The reversal of 255616391 is 193616552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 255616391 - 2⁶ = 255616327 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255616399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127808195 + 127808196.

It is an arithmetic number, because the mean of its divisors is an integer number (127808196).

Almost surely, 2^255616391 is an apocalyptic number.

255616391 is a deficient number, since it is larger than the sum of its proper divisors (1).

255616391 is an equidigital number, since it uses as much as digits as its factorization.

255616391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48600, while the sum is 38.

The square root of 255616391 is about 15988.0077245415. The cubic root of 255616391 is about 634.6431052955.

The spelling of 255616391 in words is "two hundred fifty-five million, six hundred sixteen thousand, three hundred ninety-one".