21631488 has 40 divisors (see below), whose sum is σ = 57631728. Its totient is φ = 7209984.

The previous prime is 21631483. The next prime is 21631501. The reversal of 21631488 is 88413612.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21631483) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5506 + ... + 8577.

Almost surely, 2^21631488 is an apocalyptic number.

It is an amenable number.

21631488 is an abundant number, since it is smaller than the sum of its proper divisors (36000240).

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

21631488 is an equidigital number, since it uses as much as digits as its factorization.

21631488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14104 (or 14088 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 21631488 is about 4650.9663512006. The cubic root of 21631488 is about 278.6305924116.

The spelling of 21631488 in words is "twenty-one million, six hundred thirty-one thousand, four hundred eighty-eight".