21766880 has 24 divisors (see below), whose sum is σ = 51424632. Its totient is φ = 8706688.

The previous prime is 21766873. The next prime is 21766889. The reversal of 21766880 is 8866712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21766889) 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, 67862 + ... + 68181.

It is an arithmetic number, because the mean of its divisors is an integer number (2142693).

Almost surely, 2^21766880 is an apocalyptic number.

21766880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21766880 is an abundant number, since it is smaller than the sum of its proper divisors (29657752).

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

21766880 is a wasteful number, since it uses less digits than its factorization.

21766880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136058 (or 136050 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 21766880 is about 4665.4989015110. The cubic root of 21766880 is about 279.2107022933.

The spelling of 21766880 in words is "twenty-one million, seven hundred sixty-six thousand, eight hundred eighty".