21293620 has 12 divisors (see below), whose sum is σ = 44716644. Its totient is φ = 8517440.

The previous prime is 21293599. The next prime is 21293633. The reversal of 21293620 is 2639212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7365796 + 13927824 = 2714^2 + 3732^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 532321 + ... + 532360.

It is an arithmetic number, because the mean of its divisors is an integer number (3726387).

Almost surely, 2^21293620 is an apocalyptic number.

21293620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21293620 is an abundant number, since it is smaller than the sum of its proper divisors (23423024).

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

21293620 is a wasteful number, since it uses less digits than its factorization.

21293620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1064690 (or 1064688 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21293620 is about 4614.5010564524. The cubic root of 21293620 is about 277.1723047929.

The spelling of 21293620 in words is "twenty-one million, two hundred ninety-three thousand, six hundred twenty".