21255475 has 12 divisors (see below), whose sum is σ = 26420680. Its totient is φ = 16963200.

The previous prime is 21255467. The next prime is 21255497. The reversal of 21255475 is 57455212.

It is not a de Polignac number, because 21255475 - 2³ = 21255467 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13531 + ... + 15019.

Almost surely, 2^21255475 is an apocalyptic number.

21255475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21255475 is a deficient number, since it is larger than the sum of its proper divisors (5165205).

21255475 is a wasteful number, since it uses less digits than its factorization.

21255475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2070 (or 2065 counting only the distinct ones).

The product of its digits is 14000, while the sum is 31.

The square root of 21255475 is about 4610.3660375289. The cubic root of 21255475 is about 277.0066987393.

The spelling of 21255475 in words is "twenty-one million, two hundred fifty-five thousand, four hundred seventy-five".