21631134 has 32 divisors (see below), whose sum is σ = 49616640. Its totient is φ = 6158592.

The previous prime is 21631121. The next prime is 21631171. The reversal of 21631134 is 43113612.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21631134.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14097 + ... + 15555.

It is an arithmetic number, because the mean of its divisors is an integer number (1550520).

Almost surely, 2^21631134 is an apocalyptic number.

21631134 is an abundant number, since it is smaller than the sum of its proper divisors (27985506).

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

21631134 is a wasteful number, since it uses less digits than its factorization.

21631134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1824.

The product of its digits is 432, while the sum is 21.

The square root of 21631134 is about 4650.9282944376. The cubic root of 21631134 is about 278.6290724705.

Adding to 21631134 its reverse (43113612), we get a palindrome (64744746).

The spelling of 21631134 in words is "twenty-one million, six hundred thirty-one thousand, one hundred thirty-four".