80565991 has 8 divisors (see below), whose sum is σ = 87969024. Its totient is φ = 73176120.

The previous prime is 80565967. The next prime is 80566007. The reversal of 80565991 is 19956508.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 80565991 - 2⁹ = 80565479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80565911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13080 + ... + 18226.

It is an arithmetic number, because the mean of its divisors is an integer number (10996128).

Almost surely, 2^80565991 is an apocalyptic number.

80565991 is a deficient number, since it is larger than the sum of its proper divisors (7403033).

80565991 is a wasteful number, since it uses less digits than its factorization.

80565991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6581.

The product of its (nonzero) digits is 97200, while the sum is 43.

The square root of 80565991 is about 8975.8560037469. The cubic root of 80565991 is about 431.9007098485.

The spelling of 80565991 in words is "eighty million, five hundred sixty-five thousand, nine hundred ninety-one".