20685715200 has 648 divisors, whose sum is σ = 78603802368. Its totient is φ = 5379747840.

The previous prime is 20685715159. The next prime is 20685715217. The reversal of 20685715200 is 251758602.

It is a happy number.

20685715200 is a `hidden beast` number, since 2 + 0 + 68 + 5 + 71 + 520 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (648).

It is a super-2 number, since 2×20685715200² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 73094259 + ... + 73094541.

Almost surely, 2^20685715200 is an apocalyptic number.

20685715200 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 20685715200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39301901184).

20685715200 is an abundant number, since it is smaller than the sum of its proper divisors (57918087168).

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

20685715200 is an equidigital number, since it uses as much as digits as its factorization.

20685715200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The spelling of 20685715200 in words is "twenty billion, six hundred eighty-five million, seven hundred fifteen thousand, two hundred".