21820232 has 32 divisors (see below), whose sum is σ = 48025920. Its totient is φ = 9097920.

The previous prime is 21820213. The next prime is 21820243. The reversal of 21820232 is 23202812.

It is a super-2 number, since 2×21820232² = 952245049067648, which contains 22 as substring.

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, 3194 + ... + 7337.

It is an arithmetic number, because the mean of its divisors is an integer number (1500810).

Almost surely, 2^21820232 is an apocalyptic number.

It is an amenable number.

21820232 is an abundant number, since it is smaller than the sum of its proper divisors (26205688).

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

21820232 is a wasteful number, since it uses less digits than its factorization.

21820232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10581 (or 10577 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21820232 is about 4671.2131186663. The cubic root of 21820232 is about 279.4386371991.

It can be divided in two parts, 2 and 1820232, that multiplied together give a square (3640464 = 1908²).

The spelling of 21820232 in words is "twenty-one million, eight hundred twenty thousand, two hundred thirty-two".