20651563600 has 240 divisors, whose sum is σ = 53374708800. Its totient is φ = 7656284160.

The previous prime is 20651563573. The next prime is 20651563613. The reversal of 20651563600 is 636515602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119373114 + ... + 119373286.

It is an arithmetic number, because the mean of its divisors is an integer number (222394620).

Almost surely, 2^20651563600 is an apocalyptic number.

20651563600 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 20651563600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26687354400).

20651563600 is an abundant number, since it is smaller than the sum of its proper divisors (32723145200).

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

20651563600 is a wasteful number, since it uses less digits than its factorization.

20651563600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 34.

The spelling of 20651563600 in words is "twenty billion, six hundred fifty-one million, five hundred sixty-three thousand, six hundred".