21753804 has 12 divisors (see below), whose sum is σ = 50758904. Its totient is φ = 7251264.

The previous prime is 21753793. The next prime is 21753827. The reversal of 21753804 is 40835712.

It is a tau number, because it is divible by the number of its divisors (12).

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, 906397 + ... + 906420.

Almost surely, 2^21753804 is an apocalyptic number.

It is an amenable number.

21753804 is an abundant number, since it is smaller than the sum of its proper divisors (29005100).

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

21753804 is a wasteful number, since it uses less digits than its factorization.

21753804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812824 (or 1812822 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21753804 is about 4664.0973403221. The cubic root of 21753804 is about 279.1547810885.

The spelling of 21753804 in words is "twenty-one million, seven hundred fifty-three thousand, eight hundred four".