515617993 has 4 divisors (see below), whose sum is σ = 562492368. Its totient is φ = 468743620.

The previous prime is 515617967. The next prime is 515618021. The reversal of 515617993 is 399716515.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 515617993 - 2⁵ = 515617961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (515617943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23437171 + ... + 23437192.

It is an arithmetic number, because the mean of its divisors is an integer number (140623092).

Almost surely, 2^515617993 is an apocalyptic number.

It is an amenable number.

515617993 is a deficient number, since it is larger than the sum of its proper divisors (46874375).

515617993 is a wasteful number, since it uses less digits than its factorization.

515617993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46874374.

The product of its digits is 255150, while the sum is 46.

The square root of 515617993 is about 22707.2233661450. The cubic root of 515617993 is about 801.8799501281.

The spelling of 515617993 in words is "five hundred fifteen million, six hundred seventeen thousand, nine hundred ninety-three".