991171626 has 16 divisors (see below), whose sum is σ = 2024521344. Its totient is φ = 323360864.

The previous prime is 991171607. The next prime is 991171661. The reversal of 991171626 is 626171199.

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, 1757115 + ... + 1757678.

It is an arithmetic number, because the mean of its divisors is an integer number (126532584).

Almost surely, 2^991171626 is an apocalyptic number.

991171626 is an abundant number, since it is smaller than the sum of its proper divisors (1033349718).

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

991171626 is a wasteful number, since it uses less digits than its factorization.

991171626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3514845.

The product of its digits is 40824, while the sum is 42.

The square root of 991171626 is about 31482.8782991645. The cubic root of 991171626 is about 997.0485059198.

The spelling of 991171626 in words is "nine hundred ninety-one million, one hundred seventy-one thousand, six hundred twenty-six".