660739 has 4 divisors (see below), whose sum is σ = 699624. Its totient is φ = 621856.

The previous prime is 660733. The next prime is 660757. The reversal of 660739 is 937066.

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 660739 - 2³ = 660731 is a prime.

It is a super-2 number, since 2×660739² = 873152052242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660739.

It is not an unprimeable number, because it can be changed into a prime (660731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19417 + ... + 19450.

It is an arithmetic number, because the mean of its divisors is an integer number (174906).

2⁶⁶⁰⁷³⁹ is an apocalyptic number.

660739 is a deficient number, since it is larger than the sum of its proper divisors (38885).

660739 is a wasteful number, since it uses less digits than its factorization.

660739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38884.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 660739 is about 812.8585362780. The cubic root of 660739 is about 87.0983605903.

The spelling of 660739 in words is "six hundred sixty thousand, seven hundred thirty-nine".