20918147136 has 112 divisors (see below), whose sum is σ = 57134126016. Its totient is φ = 6749374464.

The previous prime is 20918147123. The next prime is 20918147143. The reversal of 20918147136 is 63174181902.

It is a happy 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, 1392015 + ... + 1406961.

Almost surely, 2^20918147136 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 20918147136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28567063008).

20918147136 is an abundant number, since it is smaller than the sum of its proper divisors (36215978880).

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

20918147136 is a wasteful number, since it uses less digits than its factorization.

20918147136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15196 (or 15186 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The spelling of 20918147136 in words is "twenty billion, nine hundred eighteen million, one hundred forty-seven thousand, one hundred thirty-six".