518668642 has 4 divisors (see below), whose sum is σ = 778002966. Its totient is φ = 259334320.

The previous prime is 518668637. The next prime is 518668643. The reversal of 518668642 is 246866815.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 505845081 + 12823561 = 22491^2 + 3581^2 .

It is a junction number, because it is equal to n+sod(n) for n = 518668592 and 518668601.

It is not an unprimeable number, because it can be changed into a prime (518668643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129667159 + ... + 129667162.

Almost surely, 2^518668642 is an apocalyptic number.

518668642 is a deficient number, since it is larger than the sum of its proper divisors (259334324).

518668642 is a wasteful number, since it uses less digits than its factorization.

518668642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259334323.

The product of its digits is 552960, while the sum is 46.

The square root of 518668642 is about 22774.2978376941. The cubic root of 518668642 is about 803.4582798754.

The spelling of 518668642 in words is "five hundred eighteen million, six hundred sixty-eight thousand, six hundred forty-two".