20517304800 has 144 divisors (see below), whose sum is σ = 68205134592. Its totient is φ = 5354841600.

The previous prime is 20517304781. The next prime is 20517304817. The reversal of 20517304800 is 840371502.

It is a super-2 number, since 2×20517304800² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21855 + ... + 203745.

It is an arithmetic number, because the mean of its divisors is an integer number (473646768).

Almost surely, 2^20517304800 is an apocalyptic number.

20517304800 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 20517304800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34102567296).

20517304800 is an abundant number, since it is smaller than the sum of its proper divisors (47687829792).

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

20517304800 is a wasteful number, since it uses less digits than its factorization.

20517304800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181961 (or 181948 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The spelling of 20517304800 in words is "twenty billion, five hundred seventeen million, three hundred four thousand, eight hundred".