80085721 has 2 divisors, whose sum is σ = 80085722. Its totient is φ = 80085720.

The previous prime is 80085713. The next prime is 80085739. The reversal of 80085721 is 12758008.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54228496 + 25857225 = 7364^2 + 5085^2 .

It is a cyclic number.

It is not a de Polignac number, because 80085721 - 2³ = 80085713 is a prime.

It is not a weakly prime, because it can be changed into another prime (80082721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40042860 + 40042861.

It is an arithmetic number, because the mean of its divisors is an integer number (40042861).

Almost surely, 2^80085721 is an apocalyptic number.

It is an amenable number.

80085721 is a deficient number, since it is larger than the sum of its proper divisors (1).

80085721 is an equidigital number, since it uses as much as digits as its factorization.

80085721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 80085721 is about 8949.0625766054. The cubic root of 80085721 is about 431.0407833171.

The spelling of 80085721 in words is "eighty million, eighty-five thousand, seven hundred twenty-one".