21906360 has 96 divisors (see below), whose sum is σ = 81375840. Its totient is φ = 5006592.

The previous prime is 21906359. The next prime is 21906377. The reversal of 21906360 is 6360912.

It is a happy number.

21906360 is a `hidden beast` number, since 21 + 9 + 0 + 636 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1827 + ... + 6866.

It is an arithmetic number, because the mean of its divisors is an integer number (847665).

Almost surely, 2^21906360 is an apocalyptic number.

21906360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21906360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40687920).

21906360 is an abundant number, since it is smaller than the sum of its proper divisors (59469480).

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

21906360 is a wasteful number, since it uses less digits than its factorization.

21906360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8717 (or 8710 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 21906360 is about 4680.4230578015. The cubic root of 21906360 is about 279.8058177451.

The spelling of 21906360 in words is "twenty-one million, nine hundred six thousand, three hundred sixty".