20989756 has 12 divisors (see below), whose sum is σ = 38665480. Its totient is φ = 9942480.

The previous prime is 20989753. The next prime is 20989757. The reversal of 20989756 is 65798902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138015 + ... + 138166.

Almost surely, 2^20989756 is an apocalyptic number.

It is an amenable number.

20989756 is a deficient number, since it is larger than the sum of its proper divisors (17675724).

20989756 is a wasteful number, since it uses less digits than its factorization.

20989756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276204 (or 276202 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 20989756 is about 4581.4578465812. The cubic root of 20989756 is about 275.8475493586.

The spelling of 20989756 in words is "twenty million, nine hundred eighty-nine thousand, seven hundred fifty-six".