20502512640 has 352 divisors, whose sum is σ = 73802046720. Its totient is φ = 5464350720.

The previous prime is 20502512561. The next prime is 20502512677. The reversal of 20502512640 is 4621520502.

20502512640 is a `hidden beast` number, since 2 + 0 + 5 + 0 + 2 + 5 + 12 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11196525 + ... + 11198355.

Almost surely, 2^20502512640 is an apocalyptic number.

20502512640 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 20502512640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36901023360).

20502512640 is an abundant number, since it is smaller than the sum of its proper divisors (53299534080).

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

20502512640 is an frugal number, since it uses more digits than its factorization.

20502512640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1877 (or 1841 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The spelling of 20502512640 in words is "twenty billion, five hundred two million, five hundred twelve thousand, six hundred forty".