80720257 has 2 divisors, whose sum is σ = 80720258. Its totient is φ = 80720256.

The previous prime is 80720209. The next prime is 80720309. The reversal of 80720257 is 75202708.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77422401 + 3297856 = 8799^2 + 1816^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80720257 is a prime.

It is not a weakly prime, because it can be changed into another prime (80720207) 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 as a sum of consecutive naturals, namely, 40360128 + 40360129.

It is an arithmetic number, because the mean of its divisors is an integer number (40360129).

Almost surely, 2^80720257 is an apocalyptic number.

It is an amenable number.

80720257 is a deficient number, since it is larger than the sum of its proper divisors (1).

80720257 is an equidigital number, since it uses as much as digits as its factorization.

80720257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 80720257 is about 8984.4452805947. The cubic root of 80720257 is about 432.1761987720.

The spelling of 80720257 in words is "eighty million, seven hundred twenty thousand, two hundred fifty-seven".