509989901 has 2 divisors, whose sum is σ = 509989902. Its totient is φ = 509989900.

The previous prime is 509989891. The next prime is 509989937. The reversal of 509989901 is 109989905.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 323640100 + 186349801 = 17990^2 + 13651^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509989901 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 509989901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (509980901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254994950 + 254994951.

It is an arithmetic number, because the mean of its divisors is an integer number (254994951).

Almost surely, 2^509989901 is an apocalyptic number.

It is an amenable number.

509989901 is a deficient number, since it is larger than the sum of its proper divisors (1).

509989901 is an equidigital number, since it uses as much as digits as its factorization.

509989901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 262440, while the sum is 50.

The square root of 509989901 is about 22582.9559845473. The cubic root of 509989901 is about 798.9517003724.

The spelling of 509989901 in words is "five hundred nine million, nine hundred eighty-nine thousand, nine hundred one".