856961 has 6 divisors (see below), whose sum is σ = 996930. Its totient is φ = 734496.

The previous prime is 856949. The next prime is 856969. The reversal of 856961 is 169658.

It can be written as a sum of positive squares in only one way, i.e., 442225 + 414736 = 665^2 + 644^2 .

It is not a de Polignac number, because 856961 - 2⁶ = 856897 is a prime.

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 (856969) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8696 + ... + 8793.

It is an arithmetic number, because the mean of its divisors is an integer number (166155).

2⁸⁵⁶⁹⁶¹ is an apocalyptic number.

It is an amenable number.

856961 is a deficient number, since it is larger than the sum of its proper divisors (139969).

856961 is a wasteful number, since it uses less digits than its factorization.

856961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17503 (or 17496 counting only the distinct ones).

The product of its digits is 12960, while the sum is 35.

The square root of 856961 is about 925.7218804803. The cubic root of 856961 is about 94.9847066795.

The spelling of 856961 in words is "eight hundred fifty-six thousand, nine hundred sixty-one".