21766804 has 12 divisors (see below), whose sum is σ = 39121684. Its totient is φ = 10589184.

The previous prime is 21766757. The next prime is 21766831. The reversal of 21766804 is 40866712.

It can be written as a sum of positive squares in 2 ways, for example, as 10876804 + 10890000 = 3298^2 + 3300^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21766804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73389 + ... + 73684.

Almost surely, 2^21766804 is an apocalyptic number.

It is an amenable number.

21766804 is a deficient number, since it is larger than the sum of its proper divisors (17354880).

21766804 is a wasteful number, since it uses less digits than its factorization.

21766804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147114 (or 147112 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 21766804 is about 4665.4907566086. The cubic root of 21766804 is about 279.2103773342.

The spelling of 21766804 in words is "twenty-one million, seven hundred sixty-six thousand, eight hundred four".