20989507 has 12 divisors (see below), whose sum is σ = 26368048. Its totient is φ = 16354800.

The previous prime is 20989483. The next prime is 20989513. The reversal of 20989507 is 70598902.

It is not a de Polignac number, because 20989507 - 2¹⁵ = 20956739 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20989507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989567) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11544 + ... + 13237.

Almost surely, 2^20989507 is an apocalyptic number.

20989507 is a deficient number, since it is larger than the sum of its proper divisors (5378541).

20989507 is a wasteful number, since it uses less digits than its factorization.

20989507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24810 (or 24799 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 20989507 is about 4581.4306717444. The cubic root of 20989507 is about 275.8464585676.

The spelling of 20989507 in words is "twenty million, nine hundred eighty-nine thousand, five hundred seven".