660931 has 4 divisors (see below), whose sum is σ = 678832. Its totient is φ = 643032.

The previous prime is 660923. The next prime is 660941. The reversal of 660931 is 139066.

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 660931 - 2³ = 660923 is a prime.

It is a super-2 number, since 2×660931² = 873659573522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 660896 and 660905.

It is not an unprimeable number, because it can be changed into a prime (660901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8895 + ... + 8968.

It is an arithmetic number, because the mean of its divisors is an integer number (169708).

2⁶⁶⁰⁹³¹ is an apocalyptic number.

660931 is a deficient number, since it is larger than the sum of its proper divisors (17901).

660931 is a wasteful number, since it uses less digits than its factorization.

660931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17900.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 660931 is about 812.9766294304. The cubic root of 660931 is about 87.1067962286.

Adding to 660931 its reverse (139066), we get a palindrome (799997).

The spelling of 660931 in words is "six hundred sixty thousand, nine hundred thirty-one".