20518900331904 has 320 divisors, whose sum is σ = 66687383458080. Its totient is φ = 6224582246400.

The previous prime is 20518900331899. The next prime is 20518900331933. The reversal of 20518900331904 is 40913300981502.

It is a happy number.

20518900331904 is a `hidden beast` number, since 2 + 0 + 518 + 90 + 0 + 33 + 19 + 0 + 4 = 666.

It is a super-2 number, since 2×20518900331904² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20518900331904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8497584 + ... + 10641744.

Almost surely, 2^{20518900331904} is an apocalyptic number.

20518900331904 is a gapful number since it is divisible by the number (24) 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 20518900331904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33343691729040).

20518900331904 is an abundant number, since it is smaller than the sum of its proper divisors (46168483126176).

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

20518900331904 is a wasteful number, since it uses less digits than its factorization.

20518900331904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144271 (or 2144250 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 20518900331904 in words is "twenty trillion, five hundred eighteen billion, nine hundred million, three hundred thirty-one thousand, nine hundred four".