991112051 has 4 divisors (see below), whose sum is σ = 991204104. Its totient is φ = 991020000.

The previous prime is 991112027. The next prime is 991112063. The reversal of 991112051 is 150211199.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 991112051 - 2¹⁰ = 991111027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991112351) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 27350 + ... + 52251.

It is an arithmetic number, because the mean of its divisors is an integer number (247801026).

Almost surely, 2^991112051 is an apocalyptic number.

991112051 is a deficient number, since it is larger than the sum of its proper divisors (92053).

991112051 is a wasteful number, since it uses less digits than its factorization.

991112051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92052.

The product of its (nonzero) digits is 810, while the sum is 29.

The square root of 991112051 is about 31481.9321357505. The cubic root of 991112051 is about 997.0285294417.

The spelling of 991112051 in words is "nine hundred ninety-one million, one hundred twelve thousand, fifty-one".