20516418720 has 960 divisors, whose sum is σ = 89625989376. Its totient is φ = 4313088000.

The previous prime is 20516418719. The next prime is 20516418733. The reversal of 20516418720 is 2781461502.

20516418720 is a `hidden beast` number, since 2 + 0 + 5 + 1 + 641 + 8 + 7 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 81738595 + ... + 81738845.

Almost surely, 2^20516418720 is an apocalyptic number.

20516418720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20516418720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44812994688).

20516418720 is an abundant number, since it is smaller than the sum of its proper divisors (69109570656).

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

20516418720 is a wasteful number, since it uses less digits than its factorization.

20516418720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 20516418720 in words is "twenty billion, five hundred sixteen million, four hundred eighteen thousand, seven hundred twenty".