21968016 has 40 divisors (see below), whose sum is σ = 64858944. Its totient is φ = 6276480.

The previous prime is 21968003. The next prime is 21968053. The reversal of 21968016 is 61086912.

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 32355 + ... + 33026.

Almost surely, 2^21968016 is an apocalyptic number.

It is an amenable number.

21968016 is an abundant number, since it is smaller than the sum of its proper divisors (42890928).

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

21968016 is a wasteful number, since it uses less digits than its factorization.

21968016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65399 (or 65393 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21968016 is about 4687.0050138655. The cubic root of 21968016 is about 280.0680786842.

The spelling of 21968016 in words is "twenty-one million, nine hundred sixty-eight thousand, sixteen".