856215169 has 4 divisors (see below), whose sum is σ = 885739860. Its totient is φ = 826690480.

The previous prime is 856215163. The next prime is 856215229. The reversal of 856215169 is 961512658.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 961512658 = 2 ⋅480756329.

It can be written as a sum of positive squares in 2 ways, for example, as 719044225 + 137170944 = 26815^2 + 11712^2 .

It is a cyclic number.

It is not a de Polignac number, because 856215169 - 2³ = 856215161 is a prime.

It is a super-2 number, since 2×856215169² = 1466208831251397122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856215161) 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, 14762302 + ... + 14762359.

It is an arithmetic number, because the mean of its divisors is an integer number (221434965).

Almost surely, 2^856215169 is an apocalyptic number.

It is an amenable number.

856215169 is a deficient number, since it is larger than the sum of its proper divisors (29524691).

856215169 is a wasteful number, since it uses less digits than its factorization.

856215169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29524690.

The product of its digits is 129600, while the sum is 43.

The square root of 856215169 is about 29261.1546081148. The cubic root of 856215169 is about 949.5714295889.

The spelling of 856215169 in words is "eight hundred fifty-six million, two hundred fifteen thousand, one hundred sixty-nine".