20518815072 has 288 divisors, whose sum is σ = 63902678112. Its totient is φ = 5747245056.

The previous prime is 20518815049. The next prime is 20518815073. The reversal of 20518815072 is 27051881502.

It is a super-3 number, since 3×20518815072³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20518815072.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20518815073) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88063468 + ... + 88063700.

It is an arithmetic number, because the mean of its divisors is an integer number (221884299).

Almost surely, 2^20518815072 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 20518815072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31951339056).

20518815072 is an abundant number, since it is smaller than the sum of its proper divisors (43383863040).

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

20518815072 is a wasteful number, since it uses less digits than its factorization.

20518815072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 39.

The spelling of 20518815072 in words is "twenty billion, five hundred eighteen million, eight hundred fifteen thousand, seventy-two".