20197990800 has 180 divisors, whose sum is σ = 75484554964. Its totient is φ = 4971801600.

The previous prime is 20197990781. The next prime is 20197990801. The reversal of 20197990800 is 809979102.

It can be written as a sum of positive squares in 6 ways, for example, as 8742998016 + 11454992784 = 93504^2 + 107028^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (20197990801) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 168991 + ... + 262590.

Almost surely, 2^20197990800 is an apocalyptic number.

20197990800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20197990800 is an abundant number, since it is smaller than the sum of its proper divisors (55286564164).

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

20197990800 is a wasteful number, since it uses less digits than its factorization.

20197990800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431618 (or 431604 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The spelling of 20197990800 in words is "twenty billion, one hundred ninety-seven million, nine hundred ninety thousand, eight hundred".