991092091 has 8 divisors (see below), whose sum is σ = 1084716864. Its totient is φ = 898054920.

The previous prime is 991092043. The next prime is 991092097. The reversal of 991092091 is 190290199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991092091 - 2⁹ = 991091579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991092097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143365 + ... + 150118.

It is an arithmetic number, because the mean of its divisors is an integer number (135589608).

Almost surely, 2^991092091 is an apocalyptic number.

991092091 is a deficient number, since it is larger than the sum of its proper divisors (93624773).

991092091 is a wasteful number, since it uses less digits than its factorization.

991092091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293801.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 991092091 is about 31481.6151269277. The cubic root of 991092091 is about 997.0218363462.

The spelling of 991092091 in words is "nine hundred ninety-one million, ninety-two thousand, ninety-one".