21682764 has 36 divisors (see below), whose sum is σ = 56580160. Its totient is φ = 6994080.

The previous prime is 21682757. The next prime is 21682823. The reversal of 21682764 is 46728612.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8599 + ... + 10830.

Almost surely, 2^21682764 is an apocalyptic number.

It is an amenable number.

21682764 is an abundant number, since it is smaller than the sum of its proper divisors (34897396).

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

21682764 is a wasteful number, since it uses less digits than its factorization.

21682764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19470 (or 19465 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 21682764 is about 4656.4754911843. The cubic root of 21682764 is about 278.8505770972.

The spelling of 21682764 in words is "twenty-one million, six hundred eighty-two thousand, seven hundred sixty-four".