21122554 has 16 divisors (see below), whose sum is σ = 32328288. Its totient is φ = 10348272.

The previous prime is 21122473. The next prime is 21122561. The reversal of 21122554 is 45522112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37644 + ... + 38200.

It is an arithmetic number, because the mean of its divisors is an integer number (2020518).

Almost surely, 2^21122554 is an apocalyptic number.

21122554 is a deficient number, since it is larger than the sum of its proper divisors (11205734).

21122554 is a wasteful number, since it uses less digits than its factorization.

21122554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909.

The product of its digits is 800, while the sum is 22.

The square root of 21122554 is about 4595.9279802886. The cubic root of 21122554 is about 276.4280709363.

Adding to 21122554 its reverse (45522112), we get a palindrome (66644666).

The spelling of 21122554 in words is "twenty-one million, one hundred twenty-two thousand, five hundred fifty-four".