21079804 has 12 divisors (see below), whose sum is σ = 37747864. Its totient is φ = 10294704.

The previous prime is 21079801. The next prime is 21079823. The reversal of 21079804 is 40897012.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21079801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61107 + ... + 61450.

Almost surely, 2^21079804 is an apocalyptic number.

It is an amenable number.

21079804 is a deficient number, since it is larger than the sum of its proper divisors (16668060).

21079804 is a wasteful number, since it uses less digits than its factorization.

21079804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122604 (or 122602 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21079804 is about 4591.2747685147. The cubic root of 21079804 is about 276.2414571179.

It can be divided in two parts, 2107 and 9804, that added together give a palindrome (11911).

The spelling of 21079804 in words is "twenty-one million, seventy-nine thousand, eight hundred four".