21323860 has 24 divisors (see below), whose sum is σ = 44875656. Its totient is φ = 8511360.

The previous prime is 21323857. The next prime is 21323873. The reversal of 21323860 is 6832312.

It can be written as a sum of positive squares in 4 ways, for example, as 5673924 + 15649936 = 2382^2 + 3956^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12414 + ... + 14026.

It is an arithmetic number, because the mean of its divisors is an integer number (1869819).

Almost surely, 2^21323860 is an apocalyptic number.

21323860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323860 is an abundant number, since it is smaller than the sum of its proper divisors (23551796).

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

21323860 is a wasteful number, since it uses less digits than its factorization.

21323860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2283 (or 2281 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21323860 is about 4617.7765212275. The cubic root of 21323860 is about 277.3034508966.

The spelling of 21323860 in words is "twenty-one million, three hundred twenty-three thousand, eight hundred sixty".