21906852 has 24 divisors (see below), whose sum is σ = 55763232. Its totient is φ = 6638400.

The previous prime is 21906847. The next prime is 21906883. The reversal of 21906852 is 25860912.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 7 ways as a sum of consecutive naturals, for example, 82849 + ... + 83112.

It is an arithmetic number, because the mean of its divisors is an integer number (2323468).

Almost surely, 2^21906852 is an apocalyptic number.

21906852 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21906852 is an abundant number, since it is smaller than the sum of its proper divisors (33856380).

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

21906852 is a wasteful number, since it uses less digits than its factorization.

21906852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165979 (or 165977 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 21906852 is about 4680.4756168578. The cubic root of 21906852 is about 279.8079124706.

The spelling of 21906852 in words is "twenty-one million, nine hundred six thousand, eight hundred fifty-two".