21804706 has 48 divisors (see below), whose sum is σ = 42107040. Its totient is φ = 8373120.

The previous prime is 21804701. The next prime is 21804719. The reversal of 21804706 is 60740812.

It is not an unprimeable number, because it can be changed into a prime (21804701) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 121725 + ... + 121903.

It is an arithmetic number, because the mean of its divisors is an integer number (877230).

Almost surely, 2^21804706 is an apocalyptic number.

21804706 is a deficient number, since it is larger than the sum of its proper divisors (20302334).

21804706 is a wasteful number, since it uses less digits than its factorization.

21804706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21804706 is about 4669.5509420072. The cubic root of 21804706 is about 279.3723440800.

It can be divided in two parts, 2180 and 4706, that added together give a palindrome (6886).

The spelling of 21804706 in words is "twenty-one million, eight hundred four thousand, seven hundred six".