19801563400 has 24 divisors (see below), whose sum is σ = 46038635370. Its totient is φ = 7920625280.

The previous prime is 19801563391. The next prime is 19801563407. The reversal of 19801563400 is 436510891.

It can be written as a sum of positive squares in 3 ways, for example, as 14966586244 + 4834977156 = 122338^2 + 69534^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 19801563400.

It is not an unprimeable number, because it can be changed into a prime (19801563407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 49503709 + ... + 49504108.

Almost surely, 2^19801563400 is an apocalyptic number.

19801563400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19801563400 is an abundant number, since it is smaller than the sum of its proper divisors (26237071970).

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

19801563400 is a wasteful number, since it uses less digits than its factorization.

19801563400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99007833 (or 99007824 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 19801563400 in words is "nineteen billion, eight hundred one million, five hundred sixty-three thousand, four hundred".