867878989 has 2 divisors, whose sum is σ = 867878990. Its totient is φ = 867878988.

The previous prime is 867878981. The next prime is 867879029. The reversal of 867878989 is 989878768.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 559700964 + 308178025 = 23658^2 + 17555^2 .

It is a cyclic number.

It is not a de Polignac number, because 867878989 - 2³ = 867878981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (867878981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433939494 + 433939495.

It is an arithmetic number, because the mean of its divisors is an integer number (433939495).

Almost surely, 2^867878989 is an apocalyptic number.

It is an amenable number.

867878989 is a deficient number, since it is larger than the sum of its proper divisors (1).

867878989 is an equidigital number, since it uses as much as digits as its factorization.

867878989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97542144, while the sum is 70.

The square root of 867878989 is about 29459.7859632415. The cubic root of 867878989 is about 953.8638532351.

The spelling of 867878989 in words is "eight hundred sixty-seven million, eight hundred seventy-eight thousand, nine hundred eighty-nine".