80531991 has 24 divisors (see below), whose sum is σ = 121080960. Its totient is φ = 51536016.

The previous prime is 80531989. The next prime is 80531999. The reversal of 80531991 is 19913508.

It is a happy number.

It is not a de Polignac number, because 80531991 - 2¹ = 80531989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80531999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21070 + ... + 24596.

It is an arithmetic number, because the mean of its divisors is an integer number (5045040).

Almost surely, 2^80531991 is an apocalyptic number.

80531991 is a deficient number, since it is larger than the sum of its proper divisors (40548969).

80531991 is a wasteful number, since it uses less digits than its factorization.

80531991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3635 (or 3632 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 80531991 is about 8973.9618341065. The cubic root of 80531991 is about 431.8399452085.

The spelling of 80531991 in words is "eighty million, five hundred thirty-one thousand, nine hundred ninety-one".