856769 has 4 divisors (see below), whose sum is σ = 860100. Its totient is φ = 853440.

The previous prime is 856759. The next prime is 856787. The reversal of 856769 is 967658.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 967658 = 2 ⋅483829.

It can be written as a sum of positive squares in 2 ways, for example, as 313600 + 543169 = 560^2 + 737^2 .

It is a cyclic number.

It is not a de Polignac number, because 856769 - 2¹² = 852673 is a prime.

It is a super-2 number, since 2×856769² = 1468106238722, which contains 22 as substring.

It is a d-powerful number, because it can be written as 8⁵ + 5³ + 7⁷ + 6² + 6³ + 9² .

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856759) 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, 1244 + ... + 1805.

It is an arithmetic number, because the mean of its divisors is an integer number (215025).

2⁸⁵⁶⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

856769 is a deficient number, since it is larger than the sum of its proper divisors (3331).

856769 is a wasteful number, since it uses less digits than its factorization.

856769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3330.

The product of its digits is 90720, while the sum is 41.

The square root of 856769 is about 925.6181718182. The cubic root of 856769 is about 94.9776124531.

Subtracting 856769 from its reverse (967658), we obtain a square (110889 = 333²).

The spelling of 856769 in words is "eight hundred fifty-six thousand, seven hundred sixty-nine".