991190120 has 32 divisors (see below), whose sum is σ = 2231235720. Its totient is φ = 396288000.

The previous prime is 991190087. The next prime is 991190143. The reversal of 991190120 is 21091199.

It can be written as a sum of positive squares in 4 ways, for example, as 855094564 + 136095556 = 29242^2 + 11666^2 .

It is a super-2 number, since 2×991190120² = 1964915707971228800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105620 + ... + 114620.

Almost surely, 2^991190120 is an apocalyptic number.

It is an amenable number.

991190120 is an abundant number, since it is smaller than the sum of its proper divisors (1240045600).

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

991190120 is a wasteful number, since it uses less digits than its factorization.

991190120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11765 (or 11761 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 991190120 is about 31483.1720129977. The cubic root of 991190120 is about 997.0547070996.

The spelling of 991190120 in words is "nine hundred ninety-one million, one hundred ninety thousand, one hundred twenty".