518138233 has 4 divisors (see below), whose sum is σ = 521033040. Its totient is φ = 515243428.

The previous prime is 518138221. The next prime is 518138237. The reversal of 518138233 is 332831815.

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, and also an emirpimes, since its reverse is a distinct semiprime: 332831815 = 5 ⋅66566363.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518138233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (518138237) 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, 1447135 + ... + 1447492.

It is an arithmetic number, because the mean of its divisors is an integer number (130258260).

Almost surely, 2^518138233 is an apocalyptic number.

It is an amenable number.

518138233 is a deficient number, since it is larger than the sum of its proper divisors (2894807).

518138233 is a wasteful number, since it uses less digits than its factorization.

518138233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2894806.

The product of its digits is 17280, while the sum is 34.

The square root of 518138233 is about 22762.6499555742. The cubic root of 518138233 is about 803.1843047911.

The spelling of 518138233 in words is "five hundred eighteen million, one hundred thirty-eight thousand, two hundred thirty-three".