80747991 has 12 divisors (see below), whose sum is σ = 118837368. Its totient is φ = 52815984.

The previous prime is 80747987. The next prime is 80747999. The reversal of 80747991 is 19974708.

It is not a de Polignac number, because 80747991 - 2² = 80747987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80747999) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84165 + ... + 85118.

It is an arithmetic number, because the mean of its divisors is an integer number (9903114).

Almost surely, 2^80747991 is an apocalyptic number.

80747991 is a deficient number, since it is larger than the sum of its proper divisors (38089377).

80747991 is a wasteful number, since it uses less digits than its factorization.

80747991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169342 (or 169339 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 80747991 is about 8985.9885933602. The cubic root of 80747991 is about 432.2256890433.

The spelling of 80747991 in words is "eighty million, seven hundred forty-seven thousand, nine hundred ninety-one".