90991001992 has 24 divisors (see below), whose sum is σ = 187527945150. Its totient is φ = 41359545920.

The previous prime is 90991001987. The next prime is 90991002013. The reversal of 90991001992 is 29910019909.

It can be written as a sum of positive squares in only one way, i.e., 89823686436 + 1167315556 = 299706^2 + 34166^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 46998517 + ... + 47000452.

Almost surely, 2^90991001992 is an apocalyptic number.

It is an amenable number.

90991001992 is an abundant number, since it is smaller than the sum of its proper divisors (96536943158).

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

90991001992 is a wasteful number, since it uses less digits than its factorization.

90991001992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93998997 (or 93998982 counting only the distinct ones).

The product of its (nonzero) digits is 118098, while the sum is 49.

The spelling of 90991001992 in words is "ninety billion, nine hundred ninety-one million, one thousand, nine hundred ninety-two".