665474939 has 4 divisors (see below), whose sum is σ = 694408656. Its totient is φ = 636541224.

The previous prime is 665474881. The next prime is 665474941. The reversal of 665474939 is 939474566.

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 665474939 - 2⁸ = 665474683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665474989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14466824 + ... + 14466869.

It is an arithmetic number, because the mean of its divisors is an integer number (173602164).

Almost surely, 2^665474939 is an apocalyptic number.

665474939 is a deficient number, since it is larger than the sum of its proper divisors (28933717).

665474939 is a wasteful number, since it uses less digits than its factorization.

665474939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28933716.

The product of its digits is 4898880, while the sum is 53.

The square root of 665474939 is about 25796.8009450784. The cubic root of 665474939 is about 873.0596192555.

The spelling of 665474939 in words is "six hundred sixty-five million, four hundred seventy-four thousand, nine hundred thirty-nine".