21766460 has 24 divisors (see below), whose sum is σ = 48399120. Its totient is φ = 8194304.

The previous prime is 21766439. The next prime is 21766513. The reversal of 21766460 is 6466712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31670 + ... + 32349.

It is an arithmetic number, because the mean of its divisors is an integer number (2016630).

Almost surely, 2^21766460 is an apocalyptic number.

21766460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21766460 is an abundant number, since it is smaller than the sum of its proper divisors (26632660).

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

21766460 is a wasteful number, since it uses less digits than its factorization.

21766460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64045 (or 64043 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 21766460 is about 4665.4538900304. The cubic root of 21766460 is about 279.2089064572.

The spelling of 21766460 in words is "twenty-one million, seven hundred sixty-six thousand, four hundred sixty".