9191172091 has 16 divisors (see below), whose sum is σ = 9657575424. Its totient is φ = 8739745344.

The previous prime is 9191172083. The next prime is 9191172097. The reversal of 9191172091 is 1902711919.

It is a cyclic number.

It is not a de Polignac number, because 9191172091 - 2³ = 9191172083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9191172097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209886 + ... + 249868.

It is an arithmetic number, because the mean of its divisors is an integer number (603598464).

Almost surely, 2^9191172091 is an apocalyptic number.

9191172091 is a deficient number, since it is larger than the sum of its proper divisors (466403333).

9191172091 is a wasteful number, since it uses less digits than its factorization.

9191172091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40170.

The product of its (nonzero) digits is 10206, while the sum is 40.

The square root of 9191172091 is about 95870.6007647809. The cubic root of 9191172091 is about 2094.7086811336.

The spelling of 9191172091 in words is "nine billion, one hundred ninety-one million, one hundred seventy-two thousand, ninety-one".