21802836 has 24 divisors (see below), whose sum is σ = 55498464. Its totient is φ = 6606880.

The previous prime is 21802819. The next prime is 21802871. The reversal of 21802836 is 63820812.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82455 + ... + 82718.

It is an arithmetic number, because the mean of its divisors is an integer number (2312436).

Almost surely, 2^21802836 is an apocalyptic number.

It is an amenable number.

21802836 is an abundant number, since it is smaller than the sum of its proper divisors (33695628).

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

21802836 is a wasteful number, since it uses less digits than its factorization.

21802836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165191 (or 165189 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 21802836 is about 4669.3507043271. The cubic root of 21802836 is about 279.3643574063.

The spelling of 21802836 in words is "twenty-one million, eight hundred two thousand, eight hundred thirty-six".