21631113 has 24 divisors (see below), whose sum is σ = 35994816. Its totient is φ = 12261600.

The previous prime is 21631081. The next prime is 21631121. The reversal of 21631113 is 31113612.

21631113 is a `hidden beast` number, since 21 + 631 + 1 + 13 = 666.

It is not a de Polignac number, because 21631113 - 2⁵ = 21631081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21631213) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6943 + ... + 9563.

It is an arithmetic number, because the mean of its divisors is an integer number (1499784).

Almost surely, 2^21631113 is an apocalyptic number.

It is an amenable number.

21631113 is a deficient number, since it is larger than the sum of its proper divisors (14363703).

21631113 is a wasteful number, since it uses less digits than its factorization.

21631113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2765 (or 2762 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 21631113 is about 4650.9260368232. The cubic root of 21631113 is about 278.6289823039.

Adding to 21631113 its reverse (31113612), we get a palindrome (52744725).

It can be divided in two parts, 216 and 31113, that added together give a square (31329 = 177²).

The spelling of 21631113 in words is "twenty-one million, six hundred thirty-one thousand, one hundred thirteen".