21132138 has 16 divisors (see below), whose sum is σ = 43295616. Its totient is φ = 6872160.

The previous prime is 21132131. The next prime is 21132191. The reversal of 21132138 is 83123112.

It is not an unprimeable number, because it can be changed into a prime (21132131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42706 + ... + 43197.

It is an arithmetic number, because the mean of its divisors is an integer number (2705976).

Almost surely, 2^21132138 is an apocalyptic number.

21132138 is an abundant number, since it is smaller than the sum of its proper divisors (22163478).

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

21132138 is a wasteful number, since it uses less digits than its factorization.

21132138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85949.

The product of its digits is 288, while the sum is 21.

The square root of 21132138 is about 4596.9705241604. The cubic root of 21132138 is about 276.4698727948.

The spelling of 21132138 in words is "twenty-one million, one hundred thirty-two thousand, one hundred thirty-eight".