19802118400 has 81 divisors (see below), whose sum is σ = 49041217281. Its totient is φ = 7916344320.

The previous prime is 19802118247. The next prime is 19802118409. The reversal of 19802118400 is 481120891.

The square root of 19802118400 is 140720.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7128762624 + 12673355776 = 84432^2 + 112576^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19802118409) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11256721 + ... + 11258479.

Almost surely, 2^19802118400 is an apocalyptic number.

19802118400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19802118400 is the 140720-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19802118400

19802118400 is an abundant number, since it is smaller than the sum of its proper divisors (29239098881).

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

19802118400 is an frugal number, since it uses more digits than its factorization.

19802118400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3544 (or 1766 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 34.

The spelling of 19802118400 in words is "nineteen billion, eight hundred two million, one hundred eighteen thousand, four hundred".