319661 has 4 divisors (see below), whose sum is σ = 320892. Its totient is φ = 318432.

The previous prime is 319639. The next prime is 319673. The reversal of 319661 is 166913.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 166913 = 83 ⋅2011.

It can be written as a sum of positive squares in 2 ways, for example, as 244036 + 75625 = 494^2 + 275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-319661 is a prime.

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 319661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (319601) 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, 56 + ... + 801.

It is an arithmetic number, because the mean of its divisors is an integer number (80223).

2³¹⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

319661 is a deficient number, since it is larger than the sum of its proper divisors (1231).

319661 is an equidigital number, since it uses as much as digits as its factorization.

319661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230.

The product of its digits is 972, while the sum is 26.

The square root of 319661 is about 565.3857090518. The cubic root of 319661 is about 68.3748759226.

The spelling of 319661 in words is "three hundred nineteen thousand, six hundred sixty-one".