509078681 has 2 divisors, whose sum is σ = 509078682. Its totient is φ = 509078680.

The previous prime is 509078653. The next prime is 509078693. The reversal of 509078681 is 186870905.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 271425625 + 237653056 = 16475^2 + 15416^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509078681 is a prime.

It is a super-2 number, since 2×509078681² = 518322206897399522, which contains 22 as substring.

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 (509078641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254539340 + 254539341.

It is an arithmetic number, because the mean of its divisors is an integer number (254539341).

Almost surely, 2^509078681 is an apocalyptic number.

It is an amenable number.

509078681 is a deficient number, since it is larger than the sum of its proper divisors (1).

509078681 is an equidigital number, since it uses as much as digits as its factorization.

509078681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 509078681 is about 22562.7720149808. The cubic root of 509078681 is about 798.4755766996.

The spelling of 509078681 in words is "five hundred nine million, seventy-eight thousand, six hundred eighty-one".