191929997988 has 60 divisors (see below), whose sum is σ = 501793915392. Its totient is φ = 63970164720.

The previous prime is 191929997971. The next prime is 191929998053. The reversal of 191929997988 is 889799929191.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3990781 + ... + 4038587.

Almost surely, 2^191929997988 is an apocalyptic number.

191929997988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

191929997988 is an abundant number, since it is smaller than the sum of its proper divisors (309863917404).

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

191929997988 is a wasteful number, since it uses less digits than its factorization.

191929997988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60214 (or 60203 counting only the distinct ones).

The product of its digits is 476171136, while the sum is 81.

The spelling of 191929997988 in words is "one hundred ninety-one billion, nine hundred twenty-nine million, nine hundred ninety-seven thousand, nine hundred eighty-eight".