91999199020 has 24 divisors (see below), whose sum is σ = 193257845424. Its totient is φ = 36788341056.

The previous prime is 91999198981. The next prime is 91999199027. The reversal of 91999199020 is 2099199919.

It is not an unprimeable number, because it can be changed into a prime (91999199027) 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, 641974 + ... + 772093.

It is an arithmetic number, because the mean of its divisors is an integer number (8052410226).

Almost surely, 2^91999199020 is an apocalyptic number.

It is an amenable number.

91999199020 is an abundant number, since it is smaller than the sum of its proper divisors (101258646404).

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

91999199020 is a wasteful number, since it uses less digits than its factorization.

91999199020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1417329 (or 1417327 counting only the distinct ones).

The product of its (nonzero) digits is 1062882, while the sum is 58.

The spelling of 91999199020 in words is "ninety-one billion, nine hundred ninety-nine million, one hundred ninety-nine thousand, twenty".