20989964 has 6 divisors (see below), whose sum is σ = 36732444. Its totient is φ = 10494980.

The previous prime is 20989957. The next prime is 20989967. The reversal of 20989964 is 46998902.

It is not an unprimeable number, because it can be changed into a prime (20989967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2623742 + ... + 2623749.

It is an arithmetic number, because the mean of its divisors is an integer number (6122074).

Almost surely, 2^20989964 is an apocalyptic number.

It is an amenable number.

20989964 is a deficient number, since it is larger than the sum of its proper divisors (15742480).

20989964 is a wasteful number, since it uses less digits than its factorization.

20989964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5247495 (or 5247493 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 20989964 is about 4581.4805467229. The cubic root of 20989964 is about 275.8484605349.

The spelling of 20989964 in words is "twenty million, nine hundred eighty-nine thousand, nine hundred sixty-four".