664931 has 4 divisors (see below), whose sum is σ = 666600. Its totient is φ = 663264.

The previous prime is 664891. The next prime is 664933. The reversal of 664931 is 139466.

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 664931 - 2¹⁰ = 663907 is a prime.

It is a super-2 number, since 2×664931² = 884266469522, 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 = 664894 and 664903.

It is not an unprimeable number, because it can be changed into a prime (664933) 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, 155 + ... + 1163.

It is an arithmetic number, because the mean of its divisors is an integer number (166650).

2⁶⁶⁴⁹³¹ is an apocalyptic number.

664931 is a deficient number, since it is larger than the sum of its proper divisors (1669).

664931 is a wasteful number, since it uses less digits than its factorization.

664931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1668.

The product of its digits is 3888, while the sum is 29.

The square root of 664931 is about 815.4330138031. The cubic root of 664931 is about 87.2821683613.

The spelling of 664931 in words is "six hundred sixty-four thousand, nine hundred thirty-one".