21273315 has 32 divisors (see below), whose sum is σ = 39384576. Its totient is φ = 9603840.

The previous prime is 21273289. The next prime is 21273319. The reversal of 21273315 is 51337212.

It is not a de Polignac number, because 21273315 - 2⁵ = 21273283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21273319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7495 + ... + 9935.

It is an arithmetic number, because the mean of its divisors is an integer number (1230768).

Almost surely, 2^21273315 is an apocalyptic number.

21273315 is a deficient number, since it is larger than the sum of its proper divisors (18111261).

21273315 is a wasteful number, since it uses less digits than its factorization.

21273315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2539.

The product of its digits is 1260, while the sum is 24.

The square root of 21273315 is about 4612.3004021854. The cubic root of 21273315 is about 277.0841755240.

The spelling of 21273315 in words is "twenty-one million, two hundred seventy-three thousand, three hundred fifteen".