21904616 has 8 divisors (see below), whose sum is σ = 41071170. Its totient is φ = 10952304.

The previous prime is 21904609. The next prime is 21904643. The reversal of 21904616 is 61640912.

It can be written as a sum of positive squares in only one way, i.e., 14364100 + 7540516 = 3790^2 + 2746^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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, 1369031 + ... + 1369046.

Almost surely, 2^21904616 is an apocalyptic number.

It is an amenable number.

21904616 is a deficient number, since it is larger than the sum of its proper divisors (19166554).

21904616 is a wasteful number, since it uses less digits than its factorization.

21904616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2738083 (or 2738079 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 21904616 is about 4680.2367461486. The cubic root of 21904616 is about 279.7983922867.

The spelling of 21904616 in words is "twenty-one million, nine hundred four thousand, six hundred sixteen".