20990136 has 64 divisors (see below), whose sum is σ = 55756800. Its totient is φ = 6566400.

The previous prime is 20990111. The next prime is 20990143. The reversal of 20990136 is 63109902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86976 + ... + 87216.

It is an arithmetic number, because the mean of its divisors is an integer number (871200).

Almost surely, 2^20990136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20990136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27878400).

20990136 is an abundant number, since it is smaller than the sum of its proper divisors (34766664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20990136 is a wasteful number, since it uses less digits than its factorization.

20990136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 20990136 is about 4581.4993179089. The cubic root of 20990136 is about 275.8492140030.

The spelling of 20990136 in words is "twenty million, nine hundred ninety thousand, one hundred thirty-six".