20988885 has 16 divisors (see below), whose sum is σ = 33811200. Its totient is φ = 11117760.

The previous prime is 20988881. The next prime is 20988893. The reversal of 20988885 is 58888902.

It is not a de Polignac number, because 20988885 - 2² = 20988881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20988881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2461 + ... + 6930.

It is an arithmetic number, because the mean of its divisors is an integer number (2113200).

Almost surely, 2^20988885 is an apocalyptic number.

It is an amenable number.

20988885 is a deficient number, since it is larger than the sum of its proper divisors (12822315).

20988885 is a wasteful number, since it uses less digits than its factorization.

20988885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9548.

The product of its (nonzero) digits is 368640, while the sum is 48.

The square root of 20988885 is about 4581.3627885161. The cubic root of 20988885 is about 275.8437337428.

The spelling of 20988885 in words is "twenty million, nine hundred eighty-eight thousand, eight hundred eighty-five".