21820652 has 48 divisors (see below), whose sum is σ = 47050752. Its totient is φ = 8648640.

The previous prime is 21820633. The next prime is 21820661. The reversal of 21820652 is 25602812.

It is a super-2 number, since 2×21820652² = 952281707410208, which contains 22 as substring.

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, 19418 + ... + 20510.

It is an arithmetic number, because the mean of its divisors is an integer number (980224).

Almost surely, 2^21820652 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21820652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23525376).

21820652 is an abundant number, since it is smaller than the sum of its proper divisors (25230100).

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

21820652 is a wasteful number, since it uses less digits than its factorization.

21820652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158 (or 1156 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 21820652 is about 4671.2580746518. The cubic root of 21820652 is about 279.4404300837.

The spelling of 21820652 in words is "twenty-one million, eight hundred twenty thousand, six hundred fifty-two".