20999604 has 12 divisors (see below), whose sum is σ = 48999104. Its totient is φ = 6999864.

The previous prime is 20999597. The next prime is 20999623. The reversal of 20999604 is 40699902.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 874972 + ... + 874995.

Almost surely, 2^20999604 is an apocalyptic number.

It is an amenable number.

20999604 is an abundant number, since it is smaller than the sum of its proper divisors (27999500).

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

20999604 is a wasteful number, since it uses less digits than its factorization.

20999604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749974 (or 1749972 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 20999604 is about 4582.5324876099. The cubic root of 20999604 is about 275.8906834463.

The spelling of 20999604 in words is "twenty million, nine hundred ninety-nine thousand, six hundred four".