19999471788 has 108 divisors (see below), whose sum is σ = 51536637880. Its totient is φ = 6539000832.

The previous prime is 19999471769. The next prime is 19999471799. The reversal of 19999471788 is 88717499991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 63895920 + ... + 63896232.

Almost surely, 2^19999471788 is an apocalyptic number.

19999471788 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19999471788 is an abundant number, since it is smaller than the sum of its proper divisors (31537166092).

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

19999471788 is a wasteful number, since it uses less digits than its factorization.

19999471788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 570 counting only the distinct ones).

The product of its digits is 82301184, while the sum is 72.

The spelling of 19999471788 in words is "nineteen billion, nine hundred ninety-nine million, four hundred seventy-one thousand, seven hundred eighty-eight".