318661 has 4 divisors (see below), whose sum is σ = 364192. Its totient is φ = 273132.

The previous prime is 318653. The next prime is 318671. The reversal of 318661 is 166813.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166813 = 107 ⋅1559.

It is a cyclic number.

It is not a de Polignac number, because 318661 - 2³ = 318653 is a prime.

It is the 565-th Hogben number.

It is a Duffinian number.

318661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (318601) by changing a digit.

It is a nontrivial repunit in base 564.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22755 + ... + 22768.

It is an arithmetic number, because the mean of its divisors is an integer number (91048).

2³¹⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

318661 is a deficient number, since it is larger than the sum of its proper divisors (45531).

318661 is an equidigital number, since it uses as much as digits as its factorization.

318661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45530.

The product of its digits is 864, while the sum is 25.

The square root of 318661 is about 564.5006643043. The cubic root of 318661 is about 68.3035020824.

It can be divided in two parts, 318 and 661, that added together give a palindrome (979).

The spelling of 318661 in words is "three hundred eighteen thousand, six hundred sixty-one".