21629982 has 32 divisors (see below), whose sum is σ = 49248000. Its totient is φ = 6269120.

The previous prime is 21629977. The next prime is 21630013. The reversal of 21629982 is 28992612.

It is a super-2 number, since 2×21629982² = 935712242640648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21629982.

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, 5607 + ... + 8642.

It is an arithmetic number, because the mean of its divisors is an integer number (1539000).

Almost surely, 2^21629982 is an apocalyptic number.

21629982 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21629982 is an abundant number, since it is smaller than the sum of its proper divisors (27618018).

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

21629982 is a wasteful number, since it uses less digits than its factorization.

21629982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14288.

The product of its digits is 31104, while the sum is 39.

The square root of 21629982 is about 4650.8044465447. The cubic root of 21629982 is about 278.6241261064.

Subtracting from 21629982 its product of digits (31104), we obtain a triangular number (21598878 = T₆₅₇₂).

It can be divided in two parts, 21 and 629982, that added together give a triangular number (630003 = T₁₁₂₂).

The spelling of 21629982 in words is "twenty-one million, six hundred twenty-nine thousand, nine hundred eighty-two".