868686857 has 2 divisors, whose sum is σ = 868686858. Its totient is φ = 868686856.

The previous prime is 868686799. The next prime is 868686869. The reversal of 868686857 is 758686868.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 712836601 + 155850256 = 26699^2 + 12484^2 .

It is a cyclic number.

It is not a de Polignac number, because 868686857 - 2¹⁶ = 868621321 is a prime.

It is a super-3 number, since 3×868686857³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 868686857.

It is not a weakly prime, because it can be changed into another prime (868686877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 434343428 + 434343429.

It is an arithmetic number, because the mean of its divisors is an integer number (434343429).

Almost surely, 2^868686857 is an apocalyptic number.

It is an amenable number.

868686857 is a deficient number, since it is larger than the sum of its proper divisors (1).

868686857 is an equidigital number, since it uses as much as digits as its factorization.

868686857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30965760, while the sum is 62.

The square root of 868686857 is about 29473.4941430432. The cubic root of 868686857 is about 954.1597305454.

The spelling of 868686857 in words is "eight hundred sixty-eight million, six hundred eighty-six thousand, eight hundred fifty-seven".