20989982 has 16 divisors (see below), whose sum is σ = 34374480. Its totient is φ = 9554112.

The previous prime is 20989981. The next prime is 20989987. The reversal of 20989982 is 28998902.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3632 + ... + 7427.

It is an arithmetic number, because the mean of its divisors is an integer number (2148405).

Almost surely, 2^20989982 is an apocalyptic number.

20989982 is a deficient number, since it is larger than the sum of its proper divisors (13384498).

20989982 is a wasteful number, since it uses less digits than its factorization.

20989982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11147.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 20989982 is about 4581.4825111529. The cubic root of 20989982 is about 275.8485393864.

The spelling of 20989982 in words is "twenty million, nine hundred eighty-nine thousand, nine hundred eighty-two".