856866289 has 8 divisors (see below), whose sum is σ = 877194560. Its totient is φ = 836556336.

The previous prime is 856866287. The next prime is 856866341. The reversal of 856866289 is 982668658.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 856866289 - 2¹ = 856866287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856866287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153652 + ... + 159130.

It is an arithmetic number, because the mean of its divisors is an integer number (109649320).

Almost surely, 2^856866289 is an apocalyptic number.

It is an amenable number.

856866289 is a deficient number, since it is larger than the sum of its proper divisors (20328271).

856866289 is a wasteful number, since it uses less digits than its factorization.

856866289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9159.

The product of its digits is 9953280, while the sum is 58.

The square root of 856866289 is about 29272.2785071473. The cubic root of 856866289 is about 949.8120732612.

The spelling of 856866289 in words is "eight hundred fifty-six million, eight hundred sixty-six thousand, two hundred eighty-nine".