80821291 has 4 divisors (see below), whose sum is σ = 82792584. Its totient is φ = 78850000.

The previous prime is 80821271. The next prime is 80821297. The reversal of 80821291 is 19212808.

It is a happy number.

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 80821291 - 2⁷ = 80821163 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80821297) 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 3 ways as a sum of consecutive naturals, for example, 985585 + ... + 985666.

It is an arithmetic number, because the mean of its divisors is an integer number (20698146).

Almost surely, 2^80821291 is an apocalyptic number.

80821291 is a deficient number, since it is larger than the sum of its proper divisors (1971293).

80821291 is a wasteful number, since it uses less digits than its factorization.

80821291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1971292.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 80821291 is about 8990.0662400229. The cubic root of 80821291 is about 432.3564355829.

The spelling of 80821291 in words is "eighty million, eight hundred twenty-one thousand, two hundred ninety-one".