21908722 has 16 divisors (see below), whose sum is σ = 36084672. Its totient is φ = 9893520.

The previous prime is 21908713. The next prime is 21908743. The reversal of 21908722 is 22780912.

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, 283 + ... + 6625.

It is an arithmetic number, because the mean of its divisors is an integer number (2255292).

Almost surely, 2^21908722 is an apocalyptic number.

21908722 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21908722 is a deficient number, since it is larger than the sum of its proper divisors (14175950).

21908722 is a wasteful number, since it uses less digits than its factorization.

21908722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6513.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21908722 is about 4680.6753786179. The cubic root of 21908722 is about 279.8158738444.

The spelling of 21908722 in words is "twenty-one million, nine hundred eight thousand, seven hundred twenty-two".