515969393 has 4 divisors (see below), whose sum is σ = 516053220. Its totient is φ = 515885568.

The previous prime is 515969381. The next prime is 515969423. The reversal of 515969393 is 393969515.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 393969515 = 5 ⋅78793903.

It can be written as a sum of positive squares in 2 ways, for example, as 464531809 + 51437584 = 21553^2 + 7172^2 .

It is a cyclic number.

It is not a de Polignac number, because 515969393 - 2²⁰ = 514920817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (515969593) 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 in 3 ways as a sum of consecutive naturals, for example, 31880 + ... + 45257.

It is an arithmetic number, because the mean of its divisors is an integer number (129013305).

Almost surely, 2^515969393 is an apocalyptic number.

It is an amenable number.

515969393 is a deficient number, since it is larger than the sum of its proper divisors (83827).

515969393 is an equidigital number, since it uses as much as digits as its factorization.

515969393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83826.

The product of its digits is 984150, while the sum is 50.

The square root of 515969393 is about 22714.9596741883. The cubic root of 515969393 is about 802.0620724423.

The spelling of 515969393 in words is "five hundred fifteen million, nine hundred sixty-nine thousand, three hundred ninety-three".