305861 has 2 divisors, whose sum is σ = 305862. Its totient is φ = 305860.

The previous prime is 305857. The next prime is 305867. The reversal of 305861 is 168503.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297025 + 8836 = 545^2 + 94^2 .

It is a cyclic number.

It is not a de Polignac number, because 305861 - 2² = 305857 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 305861.

It is not a weakly prime, because it can be changed into another prime (305867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152930 + 152931.

It is an arithmetic number, because the mean of its divisors is an integer number (152931).

2³⁰⁵⁸⁶¹ is an apocalyptic number.

It is an amenable number.

305861 is a deficient number, since it is larger than the sum of its proper divisors (1).

305861 is an equidigital number, since it uses as much as digits as its factorization.

305861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 305861 is about 553.0470142764. The cubic root of 305861 is about 67.3764360388.

The spelling of 305861 in words is "three hundred five thousand, eight hundred sixty-one".