313661 has 2 divisors, whose sum is σ = 313662. Its totient is φ = 313660.

The previous prime is 313639. The next prime is 313669. The reversal of 313661 is 166313.

313661 is nontrivially palindromic in base 13.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 280900 + 32761 = 530^2 + 181^2 .

It is a cyclic number.

It is not a de Polignac number, because 313661 - 2⁶ = 313597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156830 + 156831.

It is an arithmetic number, because the mean of its divisors is an integer number (156831).

2³¹³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

313661 is a deficient number, since it is larger than the sum of its proper divisors (1).

313661 is an equidigital number, since it uses as much as digits as its factorization.

313661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 20.

The square root of 313661 is about 560.0544616374. The cubic root of 313661 is about 67.9443749254.

Adding to 313661 its reverse (166313), we get a palindrome (479974).

The spelling of 313661 in words is "three hundred thirteen thousand, six hundred sixty-one".