80991321 has 4 divisors (see below), whose sum is σ = 107988432. Its totient is φ = 53994212.

The previous prime is 80991301. The next prime is 80991341. The reversal of 80991321 is 12319908.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (80991301) and next prime (80991341).

It is a cyclic number.

It is not a de Polignac number, because 80991321 - 2⁵ = 80991289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (80991301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13498551 + ... + 13498556.

It is an arithmetic number, because the mean of its divisors is an integer number (26997108).

Almost surely, 2^80991321 is an apocalyptic number.

It is an amenable number.

80991321 is a deficient number, since it is larger than the sum of its proper divisors (26997111).

80991321 is a wasteful number, since it uses less digits than its factorization.

80991321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26997110.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 80991321 is about 8999.5178204168. The cubic root of 80991321 is about 432.6594171032.

The spelling of 80991321 in words is "eighty million, nine hundred ninety-one thousand, three hundred twenty-one".