21904336 has 10 divisors (see below), whose sum is σ = 42439682. Its totient is φ = 10952160.

The previous prime is 21904331. The next prime is 21904339. The reversal of 21904336 is 63340912.

It can be written as a sum of positive squares in only one way, i.e., 21902400 + 1936 = 4680^2 + 44^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21904331) 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 as a sum of consecutive naturals, namely, 684495 + ... + 684526.

Almost surely, 2^21904336 is an apocalyptic number.

It is an amenable number.

21904336 is a deficient number, since it is larger than the sum of its proper divisors (20535346).

21904336 is a wasteful number, since it uses less digits than its factorization.

21904336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1369029 (or 1369023 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 21904336 is about 4680.2068330363. The cubic root of 21904336 is about 279.7972000892.

The spelling of 21904336 in words is "twenty-one million, nine hundred four thousand, three hundred thirty-six".