80991171 has 32 divisors (see below), whose sum is σ = 125755200. Its totient is φ = 52091424.

The previous prime is 80991133. The next prime is 80991181. The reversal of 80991171 is 17119908.

It is not a de Polignac number, because 80991171 - 2⁶ = 80991107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (80991121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62785 + ... + 64061.

It is an arithmetic number, because the mean of its divisors is an integer number (3929850).

Almost surely, 2^80991171 is an apocalyptic number.

80991171 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

80991171 is a deficient number, since it is larger than the sum of its proper divisors (44764029).

80991171 is an equidigital number, since it uses as much as digits as its factorization.

80991171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327 (or 1309 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The square root of 80991171 is about 8999.5094866331. The cubic root of 80991171 is about 432.6591500007.

The spelling of 80991171 in words is "eighty million, nine hundred ninety-one thousand, one hundred seventy-one".