308681 has 2 divisors, whose sum is σ = 308682. Its totient is φ = 308680.

The previous prime is 308663. The next prime is 308701. The reversal of 308681 is 186803.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 241081 + 67600 = 491^2 + 260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-308681 is a prime.

It is a super-2 number, since 2×308681² = 190567919522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 308681.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 308681.

It is not a weakly prime, because it can be changed into another prime (308621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154340 + 154341.

It is an arithmetic number, because the mean of its divisors is an integer number (154341).

2³⁰⁸⁶⁸¹ is an apocalyptic number.

It is an amenable number.

308681 is a deficient number, since it is larger than the sum of its proper divisors (1).

308681 is an equidigital number, since it uses as much as digits as its factorization.

308681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 308681 is about 555.5906766676. The cubic root of 308681 is about 67.5828703257.

It can be divided in two parts, 308 and 681, that added together give a palindrome (989).

The spelling of 308681 in words is "three hundred eight thousand, six hundred eighty-one".