72808709 has 2 divisors, whose sum is σ = 72808710. Its totient is φ = 72808708.

The previous prime is 72808693. The next prime is 72808717. The reversal of 72808709 is 90780827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57047809 + 15760900 = 7553^2 + 3970^2 .

It is a cyclic number.

It is not a de Polignac number, because 72808709 - 2⁴ = 72808693 is a prime.

It is a super-2 number, since 2×72808709² = 10602216212493362, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72888709) 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, 36404354 + 36404355.

It is an arithmetic number, because the mean of its divisors is an integer number (36404355).

Almost surely, 2^72808709 is an apocalyptic number.

It is an amenable number.

72808709 is a deficient number, since it is larger than the sum of its proper divisors (1).

72808709 is an equidigital number, since it uses as much as digits as its factorization.

72808709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 72808709 is about 8532.8019430900. The cubic root of 72808709 is about 417.5685455242.

The spelling of 72808709 in words is "seventy-two million, eight hundred eight thousand, seven hundred nine".