91919091900 has 144 divisors (see below), whose sum is σ = 272661243008. Its totient is φ = 23895648000.

The previous prime is 91919091877. The next prime is 91919091959. The reversal of 91919091900 is 919091919.

It is a super-2 number, since 2×91919091900² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91919091900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6972315 + ... + 6985485.

Almost surely, 2^91919091900 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 91919091900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136330621504).

91919091900 is an abundant number, since it is smaller than the sum of its proper divisors (180742151108).

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

91919091900 is a wasteful number, since it uses less digits than its factorization.

91919091900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13772 (or 13765 counting only the distinct ones).

The product of its (nonzero) digits is 59049, while the sum is 48.

The spelling of 91919091900 in words is "ninety-one billion, nine hundred nineteen million, ninety-one thousand, nine hundred".