864581813 has 2 divisors, whose sum is σ = 864581814. Its totient is φ = 864581812.

The previous prime is 864581761. The next prime is 864581819. The reversal of 864581813 is 318185468.

It is a happy number.

864581813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 688170289 + 176411524 = 26233^2 + 13282^2 .

It is a cyclic number.

It is not a de Polignac number, because 864581813 - 2⁶ = 864581749 is a prime.

It is a super-2 number, since 2×864581813² = 1495003422740733938, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (864581819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432290906 + 432290907.

It is an arithmetic number, because the mean of its divisors is an integer number (432290907).

Almost surely, 2^864581813 is an apocalyptic number.

It is an amenable number.

864581813 is a deficient number, since it is larger than the sum of its proper divisors (1).

864581813 is an equidigital number, since it uses as much as digits as its factorization.

864581813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 184320, while the sum is 44.

The square root of 864581813 is about 29403.7720879482. The cubic root of 864581813 is about 952.6543726940.

The spelling of 864581813 in words is "eight hundred sixty-four million, five hundred eighty-one thousand, eight hundred thirteen".