21631160 has 16 divisors (see below), whose sum is σ = 48670200. Its totient is φ = 8652448.

The previous prime is 21631121. The next prime is 21631171. The reversal of 21631160 is 6113612.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270350 + ... + 270429.

Almost surely, 2^21631160 is an apocalyptic number.

21631160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21631160 is an abundant number, since it is smaller than the sum of its proper divisors (27039040).

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

21631160 is a wasteful number, since it uses less digits than its factorization.

21631160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540790 (or 540786 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21631160 is about 4650.9310895777. The cubic root of 21631160 is about 278.6291841051.

Adding to 21631160 its reverse (6113612), we get a palindrome (27744772).

The spelling of 21631160 in words is "twenty-one million, six hundred thirty-one thousand, one hundred sixty".