75990809 has 2 divisors, whose sum is σ = 75990810. Its totient is φ = 75990808.

The previous prime is 75990793. The next prime is 75990829. The reversal of 75990809 is 90809957.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67158025 + 8832784 = 8195^2 + 2972^2 .

It is a cyclic number.

It is not a de Polignac number, because 75990809 - 2⁴ = 75990793 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (75990829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37995404 + 37995405.

It is an arithmetic number, because the mean of its divisors is an integer number (37995405).

Almost surely, 2^75990809 is an apocalyptic number.

It is an amenable number.

75990809 is a deficient number, since it is larger than the sum of its proper divisors (1).

75990809 is an equidigital number, since it uses as much as digits as its factorization.

75990809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204120, while the sum is 47.

The square root of 75990809 is about 8717.2707311406. The cubic root of 75990809 is about 423.5652825377.

The spelling of 75990809 in words is "seventy-five million, nine hundred ninety thousand, eight hundred nine".