255645621 has 96 divisors (see below), whose sum is σ = 492890112. Its totient is φ = 123742080.

The previous prime is 255645613. The next prime is 255645631. The reversal of 255645621 is 126546552.

255645621 is a `hidden beast` number, since 2 + 5 + 5 + 645 + 6 + 2 + 1 = 666.

It is not a de Polignac number, because 255645621 - 2³ = 255645613 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255645631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 685191 + ... + 685563.

It is an arithmetic number, because the mean of its divisors is an integer number (5134272).

Almost surely, 2^255645621 is an apocalyptic number.

255645621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

255645621 is a deficient number, since it is larger than the sum of its proper divisors (237244491).

255645621 is a wasteful number, since it uses less digits than its factorization.

255645621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463 (or 460 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 255645621 is about 15988.9218210610. The cubic root of 255645621 is about 634.6672950730.

The spelling of 255645621 in words is "two hundred fifty-five million, six hundred forty-five thousand, six hundred twenty-one".