818211857 has 2 divisors, whose sum is σ = 818211858. Its totient is φ = 818211856.

The previous prime is 818211847. The next prime is 818211871. The reversal of 818211857 is 758112818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 610880656 + 207331201 = 24716^2 + 14399^2 .

It is a cyclic number.

It is not a de Polignac number, because 818211857 - 2¹⁶ = 818146321 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (818211817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409105928 + 409105929.

It is an arithmetic number, because the mean of its divisors is an integer number (409105929).

Almost surely, 2^818211857 is an apocalyptic number.

It is an amenable number.

818211857 is a deficient number, since it is larger than the sum of its proper divisors (1).

818211857 is an equidigital number, since it uses as much as digits as its factorization.

818211857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35840, while the sum is 41.

The square root of 818211857 is about 28604.4027555200. The cubic root of 818211857 is about 935.3093077154.

The spelling of 818211857 in words is "eight hundred eighteen million, two hundred eleven thousand, eight hundred fifty-seven".