660043939 has 4 divisors (see below), whose sum is σ = 660500280. Its totient is φ = 659587600.

The previous prime is 660043933. The next prime is 660043957. The reversal of 660043939 is 939340066.

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

It is a cyclic number.

It is not a de Polignac number, because 660043939 - 2³ = 660043931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660043931) 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 in 3 ways as a sum of consecutive naturals, for example, 225994 + ... + 228895.

It is an arithmetic number, because the mean of its divisors is an integer number (165125070).

Almost surely, 2^660043939 is an apocalyptic number.

660043939 is a deficient number, since it is larger than the sum of its proper divisors (456341).

660043939 is a wasteful number, since it uses less digits than its factorization.

660043939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456340.

The product of its (nonzero) digits is 104976, while the sum is 40.

The square root of 660043939 is about 25691.3203047255. The cubic root of 660043939 is about 870.6780898379.

The spelling of 660043939 in words is "six hundred sixty million, forty-three thousand, nine hundred thirty-nine".