865988 has 12 divisors (see below), whose sum is σ = 1526700. Its totient is φ = 429792.

The previous prime is 865979. The next prime is 865993. The reversal of 865988 is 889568.

865988 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 515524 + 350464 = 718^2 + 592^2 .

It is a super-2 number, since 2×865988² = 1499870432288, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131 + ... + 1322.

It is an arithmetic number, because the mean of its divisors is an integer number (127225).

2⁸⁶⁵⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

865988 is a deficient number, since it is larger than the sum of its proper divisors (660712).

865988 is a wasteful number, since it uses less digits than its factorization.

865988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606 (or 1604 counting only the distinct ones).

The product of its digits is 138240, while the sum is 44.

The square root of 865988 is about 930.5847623941. The cubic root of 865988 is about 95.3170570069.

The spelling of 865988 in words is "eight hundred sixty-five thousand, nine hundred eighty-eight".