991858192 has 20 divisors (see below), whose sum is σ = 2069550700. Its totient is φ = 457780608.

The previous prime is 991858181. The next prime is 991858199. The reversal of 991858192 is 291858199.

It can be written as a sum of positive squares in 2 ways, for example, as 77158656 + 914699536 = 8784^2 + 30244^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

It is not an unprimeable number, because it can be changed into a prime (991858199) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2384067 + ... + 2384482.

It is an arithmetic number, because the mean of its divisors is an integer number (103477535).

Almost surely, 2^991858192 is an apocalyptic number.

It is an amenable number.

991858192 is an abundant number, since it is smaller than the sum of its proper divisors (1077692508).

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

991858192 is a wasteful number, since it uses less digits than its factorization.

991858192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4768570 (or 4768564 counting only the distinct ones).

The product of its digits is 466560, while the sum is 52.

The square root of 991858192 is about 31493.7802113370. The cubic root of 991858192 is about 997.2786650539.

The spelling of 991858192 in words is "nine hundred ninety-one million, eight hundred fifty-eight thousand, one hundred ninety-two".