868561 has 2 divisors, whose sum is σ = 868562. Its totient is φ = 868560.

The previous prime is 868559. The next prime is 868577. The reversal of 868561 is 165868.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 571536 + 297025 = 756^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 868561 - 2¹ = 868559 is a prime.

Together with 868559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (868531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 434280 + 434281.

It is an arithmetic number, because the mean of its divisors is an integer number (434281).

2⁸⁶⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

868561 is a deficient number, since it is larger than the sum of its proper divisors (1).

868561 is an equidigital number, since it uses as much as digits as its factorization.

868561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 868561 is about 931.9662011039. The cubic root of 868561 is about 95.4113648163.

The spelling of 868561 in words is "eight hundred sixty-eight thousand, five hundred sixty-one".