21169968 has 20 divisors (see below), whose sum is σ = 54689208. Its totient is φ = 7056640.

The previous prime is 21169963. The next prime is 21169969. The reversal of 21169968 is 86996112.

It is not an unprimeable number, because it can be changed into a prime (21169963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220473 + ... + 220568.

Almost surely, 2^21169968 is an apocalyptic number.

It is an amenable number.

21169968 is an abundant number, since it is smaller than the sum of its proper divisors (33519240).

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

21169968 is a wasteful number, since it uses less digits than its factorization.

21169968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441052 (or 441046 counting only the distinct ones).

The product of its digits is 46656, while the sum is 42.

The square root of 21169968 is about 4601.0833506904. The cubic root of 21169968 is about 276.6347499512.

The spelling of 21169968 in words is "twenty-one million, one hundred sixty-nine thousand, nine hundred sixty-eight".