515209993 has 2 divisors, whose sum is σ = 515209994. Its totient is φ = 515209992.

The previous prime is 515209991. The next prime is 515210039. The reversal of 515209993 is 399902515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 400120009 + 115089984 = 20003^2 + 10728^2 .

It is a cyclic number.

It is not a de Polignac number, because 515209993 - 2¹ = 515209991 is a prime.

Together with 515209991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (515209991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 257604996 + 257604997.

It is an arithmetic number, because the mean of its divisors is an integer number (257604997).

Almost surely, 2^515209993 is an apocalyptic number.

It is an amenable number.

515209993 is a deficient number, since it is larger than the sum of its proper divisors (1).

515209993 is an equidigital number, since it uses as much as digits as its factorization.

515209993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 109350, while the sum is 43.

The square root of 515209993 is about 22698.2376628671. The cubic root of 515209993 is about 801.6683895309.

The spelling of 515209993 in words is "five hundred fifteen million, two hundred nine thousand, nine hundred ninety-three".