80043991 has 2 divisors, whose sum is σ = 80043992. Its totient is φ = 80043990.

The previous prime is 80043983. The next prime is 80044001. The reversal of 80043991 is 19934008.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 80043991 - 2³ = 80043983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80043911) 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 as a sum of consecutive naturals, namely, 40021995 + 40021996.

It is an arithmetic number, because the mean of its divisors is an integer number (40021996).

Almost surely, 2^80043991 is an apocalyptic number.

80043991 is a deficient number, since it is larger than the sum of its proper divisors (1).

80043991 is an equidigital number, since it uses as much as digits as its factorization.

80043991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 80043991 is about 8946.7307436851. The cubic root of 80043991 is about 430.9659033145.

Adding to 80043991 its reverse (19934008), we get a palindrome (99977999).

The spelling of 80043991 in words is "eighty million, forty-three thousand, nine hundred ninety-one".