865961 has 4 divisors (see below), whose sum is σ = 887124. Its totient is φ = 844800.

The previous prime is 865957. The next prime is 865979. The reversal of 865961 is 169568.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 570025 = 544^2 + 755^2 .

It is a cyclic number.

It is not a de Polignac number, because 865961 - 2² = 865957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (865061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10520 + ... + 10601.

It is an arithmetic number, because the mean of its divisors is an integer number (221781).

2⁸⁶⁵⁹⁶¹ is an apocalyptic number.

It is an amenable number.

865961 is a deficient number, since it is larger than the sum of its proper divisors (21163).

865961 is a wasteful number, since it uses less digits than its factorization.

865961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21162.

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

The square root of 865961 is about 930.5702552736. The cubic root of 865961 is about 95.3160663899.

The spelling of 865961 in words is "eight hundred sixty-five thousand, nine hundred sixty-one".