509698121 has 2 divisors, whose sum is σ = 509698122. Its totient is φ = 509698120.

The previous prime is 509698093. The next prime is 509698151. The reversal of 509698121 is 121896905.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397444096 + 112254025 = 19936^2 + 10595^2 .

It is a cyclic number.

It is not a de Polignac number, because 509698121 - 2¹⁴ = 509681737 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (509698151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254849060 + 254849061.

It is an arithmetic number, because the mean of its divisors is an integer number (254849061).

Almost surely, 2^509698121 is an apocalyptic number.

It is an amenable number.

509698121 is a deficient number, since it is larger than the sum of its proper divisors (1).

509698121 is an equidigital number, since it uses as much as digits as its factorization.

509698121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 41.

The square root of 509698121 is about 22576.4948785235. The cubic root of 509698121 is about 798.7993034990.

The spelling of 509698121 in words is "five hundred nine million, six hundred ninety-eight thousand, one hundred twenty-one".