864187889 has 2 divisors, whose sum is σ = 864187890. Its totient is φ = 864187888.

The previous prime is 864187879. The next prime is 864187937. The reversal of 864187889 is 988781468.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 459373489 + 404814400 = 21433^2 + 20120^2 .

It is a cyclic number.

It is not a de Polignac number, because 864187889 - 2¹⁶ = 864122353 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (864187879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432093944 + 432093945.

It is an arithmetic number, because the mean of its divisors is an integer number (432093945).

Almost surely, 2^864187889 is an apocalyptic number.

It is an amenable number.

864187889 is a deficient number, since it is larger than the sum of its proper divisors (1).

864187889 is an equidigital number, since it uses as much as digits as its factorization.

864187889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6193152, while the sum is 59.

The square root of 864187889 is about 29397.0727964537. The cubic root of 864187889 is about 952.5096667316.

The spelling of 864187889 in words is "eight hundred sixty-four million, one hundred eighty-seven thousand, eight hundred eighty-nine".