665938384138 has 8 divisors (see below), whose sum is σ = 1022137985088. Its totient is φ = 325225722444.

The previous prime is 665938384127. The next prime is 665938384201. The reversal of 665938384138 is 831483839566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 665938384138.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3871734706 + ... + 3871734877.

It is an arithmetic number, because the mean of its divisors is an integer number (127767248136).

Almost surely, 2^665938384138 is an apocalyptic number.

665938384138 is a deficient number, since it is larger than the sum of its proper divisors (356199600950).

665938384138 is a wasteful number, since it uses less digits than its factorization.

665938384138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7743469628.

The product of its digits is 89579520, while the sum is 64.

The spelling of 665938384138 in words is "six hundred sixty-five billion, nine hundred thirty-eight million, three hundred eighty-four thousand, one hundred thirty-eight".