99878939491968 has 1024 divisors, whose sum is σ = 376011683712000. Its totient is φ = 25386411294720.

The previous prime is 99878939491951. The next prime is 99878939491973. The reversal of 99878939491968 is 86919493987899.

99878939491968 is a `hidden beast` number, since 9 + 9 + 8 + 78 + 9 + 39 + 491 + 9 + 6 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5080044058 + ... + 5080063718.

It is an arithmetic number, because the mean of its divisors is an integer number (367198909875).

Almost surely, 2^{99878939491968} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99878939491968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188005841856000).

99878939491968 is an abundant number, since it is smaller than the sum of its proper divisors (276132744220032).

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

99878939491968 is a wasteful number, since it uses less digits than its factorization.

99878939491968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20290 (or 20272 counting only the distinct ones).

The product of its digits is 137137287168, while the sum is 99.

The spelling of 99878939491968 in words is "ninety-nine trillion, eight hundred seventy-eight billion, nine hundred thirty-nine million, four hundred ninety-one thousand, nine hundred sixty-eight".