19881000000 has 441 divisors, whose sum is σ = 72778502017. Its totient is φ = 5188800000.

The previous prime is 19880999977. The next prime is 19881000001. The reversal of 19881000000 is 18891.

The square root of 19881000000 is 141000.

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

It can be written as a sum of positive squares in 3 ways, for example, as 17417664576 + 2463335424 = 131976^2 + 49632^2 .

It is a super-2 number, since 2×19881000000² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19881000001) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 422999977 + ... + 423000023.

Almost surely, 2^19881000000 is an apocalyptic number.

19881000000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19881000000 is the 141000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19881000000

19881000000 is an abundant number, since it is smaller than the sum of its proper divisors (52897502017).

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

19881000000 is an frugal number, since it uses more digits than its factorization.

19881000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

Multiplying 19881000000 by its product of nonzero digits (576), we get a square (11451456000000 = 3384000²).

19881000000 divided by its product of nonzero digits (576) gives a square (34515625 = 5875²).

Adding to 19881000000 its reverse (18891), we get a palindrome (19881018891).

The spelling of 19881000000 in words is "nineteen billion, eight hundred eighty-one million", and thus it is an aban number.