21358984 has 8 divisors (see below), whose sum is σ = 40048110. Its totient is φ = 10679488.

The previous prime is 21358979. The next prime is 21358999. The reversal of 21358984 is 48985312.

It can be written as a sum of positive squares in only one way, i.e., 16990884 + 4368100 = 4122^2 + 2090^2 .

It is a tau number, because it is divible by the number of its divisors (8).

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 as a sum of consecutive naturals, namely, 1334929 + ... + 1334944.

Almost surely, 2^21358984 is an apocalyptic number.

It is an amenable number.

21358984 is a deficient number, since it is larger than the sum of its proper divisors (18689126).

21358984 is a wasteful number, since it uses less digits than its factorization.

21358984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2669879 (or 2669875 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 21358984 is about 4621.5780854596. The cubic root of 21358984 is about 277.4556225873.

The spelling of 21358984 in words is "twenty-one million, three hundred fifty-eight thousand, nine hundred eighty-four".