91999999992 has 32 divisors (see below), whose sum is σ = 230012830080. Its totient is φ = 30664956000.

The previous prime is 91999999991. The next prime is 92000000011. The reversal of 91999999992 is 29999999919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91999999991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376983 + ... + 571065.

It is an arithmetic number, because the mean of its divisors is an integer number (7187900940).

Almost surely, 2^91999999992 is an apocalyptic number.

It is an amenable number.

91999999992 is an abundant number, since it is smaller than the sum of its proper divisors (138012830088).

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

91999999992 is a wasteful number, since it uses less digits than its factorization.

91999999992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213843 (or 213839 counting only the distinct ones).

The product of its digits is 774840978, while the sum is 84.

The spelling of 91999999992 in words is "ninety-one billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-two".