91990430850 has 96 divisors (see below), whose sum is σ = 241958335104. Its totient is φ = 23079513600.

The previous prime is 91990430839. The next prime is 91990430869. The reversal of 91990430850 is 5803409919.

It is a self number, because there is not a number n which added to its sum of digits gives 91990430850.

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, 8107 + ... + 429006.

It is an arithmetic number, because the mean of its divisors is an integer number (2520399324).

Almost surely, 2^91990430850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91990430850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120979167552).

91990430850 is an abundant number, since it is smaller than the sum of its proper divisors (149967904254).

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

91990430850 is a wasteful number, since it uses less digits than its factorization.

91990430850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437212 (or 437207 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 48.

The spelling of 91990430850 in words is "ninety-one billion, nine hundred ninety million, four hundred thirty thousand, eight hundred fifty".