20861604 has 24 divisors (see below), whose sum is σ = 54085920. Its totient is φ = 6953832.

The previous prime is 20861597. The next prime is 20861623. The reversal of 20861604 is 40616802.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96474 + ... + 96689.

It is an arithmetic number, because the mean of its divisors is an integer number (2253580).

Almost surely, 2^20861604 is an apocalyptic number.

It is an amenable number.

20861604 is an abundant number, since it is smaller than the sum of its proper divisors (33224316).

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

20861604 is a wasteful number, since it uses less digits than its factorization.

20861604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193176 (or 193168 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20861604 is about 4567.4504923425. The cubic root of 20861604 is about 275.2850113977.

The spelling of 20861604 in words is "twenty million, eight hundred sixty-one thousand, six hundred four".