20985604 has 18 divisors (see below), whose sum is σ = 37654442. Its totient is φ = 10233600.

The previous prime is 20985593. The next prime is 20985617. The reversal of 20985604 is 40658902.

It is a happy number.

20985604 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 3 ways, for example, as 5760000 + 15225604 = 2400^2 + 3902^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20985604.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5164 + ... + 8284.

Almost surely, 2^20985604 is an apocalyptic number.

It is an amenable number.

20985604 is a deficient number, since it is larger than the sum of its proper divisors (16668838).

20985604 is a wasteful number, since it uses less digits than its factorization.

20985604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3207 (or 3164 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20985604 is about 4581.0046932960. The cubic root of 20985604 is about 275.8293596196.

The spelling of 20985604 in words is "twenty million, nine hundred eighty-five thousand, six hundred four".