840878289 has 12 divisors (see below), whose sum is σ = 1215066996. Its totient is φ = 560370912.

The previous prime is 840878267. The next prime is 840878309. The reversal of 840878289 is 982878048.

It can be written as a sum of positive squares in 2 ways, for example, as 35283600 + 805594689 = 5940^2 + 28383^2 .

It is not a de Polignac number, because 840878289 - 2⁵ = 840878257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840878239) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9067 + ... + 41999.

It is an arithmetic number, because the mean of its divisors is an integer number (101255583).

Almost surely, 2^840878289 is an apocalyptic number.

It is an amenable number.

840878289 is a deficient number, since it is larger than the sum of its proper divisors (374188707).

840878289 is a wasteful number, since it uses less digits than its factorization.

840878289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35776 (or 35773 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 54.

The square root of 840878289 is about 28997.9014585539. The cubic root of 840878289 is about 943.8675306223.

The spelling of 840878289 in words is "eight hundred forty million, eight hundred seventy-eight thousand, two hundred eighty-nine".