21132356 has 24 divisors (see below), whose sum is σ = 42645120. Its totient is φ = 8975232.

The previous prime is 21132341. The next prime is 21132383. The reversal of 21132356 is 65323112.

It is a super-2 number, since 2×21132356² = 893152940221472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 176 + ... + 6503.

It is an arithmetic number, because the mean of its divisors is an integer number (1776880).

Almost surely, 2^21132356 is an apocalyptic number.

It is an amenable number.

21132356 is an abundant number, since it is smaller than the sum of its proper divisors (21512764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21132356 is a wasteful number, since it uses less digits than its factorization.

21132356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6803 (or 6801 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 21132356 is about 4596.9942353673. The cubic root of 21132356 is about 276.4708234831.

Adding to 21132356 its reverse (65323112), we get a palindrome (86455468).

The spelling of 21132356 in words is "twenty-one million, one hundred thirty-two thousand, three hundred fifty-six".