856531 has 8 divisors (see below), whose sum is σ = 945504. Its totient is φ = 770880.

The previous prime is 856529. The next prime is 856547. The reversal of 856531 is 135658.

856531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 856531 - 2¹ = 856529 is a prime.

It is a super-2 number, since 2×856531² = 1467290707922, which contains 22 as substring.

It is a Duffinian number.

856531 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 856531.

It is not an unprimeable number, because it can be changed into a prime (856571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271 + ... + 1336.

It is an arithmetic number, because the mean of its divisors is an integer number (118188).

2⁸⁵⁶⁵³¹ is an apocalyptic number.

856531 is a deficient number, since it is larger than the sum of its proper divisors (88973).

856531 is a wasteful number, since it uses less digits than its factorization.

856531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1661.

The product of its digits is 3600, while the sum is 28.

The square root of 856531 is about 925.4896001577. The cubic root of 856531 is about 94.9688170971.

The spelling of 856531 in words is "eight hundred fifty-six thousand, five hundred thirty-one".