19866902500 has 45 divisors (see below), whose sum is σ = 43460359327. Its totient is φ = 7943942000.

The previous prime is 19866902467. The next prime is 19866902563. The reversal of 19866902500 is 520966891.

The square root of 19866902500 is 140950.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1557565156 + 18309337344 = 39466^2 + 135312^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 7046091 + ... + 7048909.

Almost surely, 2^19866902500 is an apocalyptic number.

19866902500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19866902500 is the 140950-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19866902500

19866902500 is an abundant number, since it is smaller than the sum of its proper divisors (23593456827).

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

19866902500 is an frugal number, since it uses more digits than its factorization.

19866902500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5662 (or 2826 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 19866902500 in words is "nineteen billion, eight hundred sixty-six million, nine hundred two thousand, five hundred".