21976064 has 44 divisors (see below), whose sum is σ = 47948928. Its totient is φ = 9984000.

The previous prime is 21976057. The next prime is 21976069. The reversal of 21976064 is 46067912.

It is a tau number, because it is divible by the number of its divisors (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21976069) 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, 10289 + ... + 12239.

Almost surely, 2^21976064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21976064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23974464).

21976064 is an abundant number, since it is smaller than the sum of its proper divisors (25972864).

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

21976064 is a wasteful number, since it uses less digits than its factorization.

21976064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1982 (or 1964 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 21976064 is about 4687.8634792408. The cubic root of 21976064 is about 280.1022755624.

The spelling of 21976064 in words is "twenty-one million, nine hundred seventy-six thousand, sixty-four".