855918689 has 4 divisors (see below), whose sum is σ = 856000020. Its totient is φ = 855837360.

The previous prime is 855918671. The next prime is 855918697. The reversal of 855918689 is 986819558.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 986819558 = 2 ⋅493409779.

It can be written as a sum of positive squares in 2 ways, for example, as 749828689 + 106090000 = 27383^2 + 10300^2 .

It is a cyclic number.

It is not a de Polignac number, because 855918689 - 2⁸ = 855918433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855912689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22034 + ... + 46875.

It is an arithmetic number, because the mean of its divisors is an integer number (214000005).

Almost surely, 2^855918689 is an apocalyptic number.

It is an amenable number.

855918689 is a deficient number, since it is larger than the sum of its proper divisors (81331).

855918689 is a wasteful number, since it uses less digits than its factorization.

855918689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81330.

The product of its digits is 6220800, while the sum is 59.

The square root of 855918689 is about 29256.0880672724. The cubic root of 855918689 is about 949.4618148375.

The spelling of 855918689 in words is "eight hundred fifty-five million, nine hundred eighteen thousand, six hundred eighty-nine".