21330986 has 16 divisors (see below), whose sum is σ = 32545800. Its totient is φ = 10483968.

The previous prime is 21330983. The next prime is 21331001. The reversal of 21330986 is 68903312.

It can be written as a sum of positive squares in 4 ways, for example, as 21298225 + 32761 = 4615^2 + 181^2 .

It is not an unprimeable number, because it can be changed into a prime (21330983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51950 + ... + 52358.

Almost surely, 2^21330986 is an apocalyptic number.

21330986 is a deficient number, since it is larger than the sum of its proper divisors (11214814).

21330986 is a wasteful number, since it uses less digits than its factorization.

21330986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21330986 is about 4618.5480402395. The cubic root of 21330986 is about 277.3343371794.

The spelling of 21330986 in words is "twenty-one million, three hundred thirty thousand, nine hundred eighty-six".