868859861 has 2 divisors, whose sum is σ = 868859862. Its totient is φ = 868859860.

The previous prime is 868859857. The next prime is 868859879. The reversal of 868859861 is 168958868.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609843025 + 259016836 = 24695^2 + 16094^2 .

It is a cyclic number.

It is not a de Polignac number, because 868859861 - 2² = 868859857 is a prime.

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 868859861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (868859801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 434429930 + 434429931.

It is an arithmetic number, because the mean of its divisors is an integer number (434429931).

Almost surely, 2^868859861 is an apocalyptic number.

It is an amenable number.

868859861 is a deficient number, since it is larger than the sum of its proper divisors (1).

868859861 is an equidigital number, since it uses as much as digits as its factorization.

868859861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6635520, while the sum is 59.

The square root of 868859861 is about 29476.4289051439. The cubic root of 868859861 is about 954.2230684796.

The spelling of 868859861 in words is "eight hundred sixty-eight million, eight hundred fifty-nine thousand, eight hundred sixty-one".