80665971 has 4 divisors (see below), whose sum is σ = 107554632. Its totient is φ = 53777312.

The previous prime is 80665961. The next prime is 80665987. The reversal of 80665971 is 17956608.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 80665971 - 2⁵ = 80665939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (80665931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13444326 + ... + 13444331.

It is an arithmetic number, because the mean of its divisors is an integer number (26888658).

Almost surely, 2^80665971 is an apocalyptic number.

80665971 is a deficient number, since it is larger than the sum of its proper divisors (26888661).

80665971 is a wasteful number, since it uses less digits than its factorization.

80665971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26888660.

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 80665971 is about 8981.4236622041. The cubic root of 80665971 is about 432.0792946436.

The spelling of 80665971 in words is "eighty million, six hundred sixty-five thousand, nine hundred seventy-one".