865986971 has 4 divisors (see below), whose sum is σ = 866202744. Its totient is φ = 865771200.

The previous prime is 865986967. The next prime is 865986977. The reversal of 865986971 is 179689568.

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

It is a cyclic number.

It is not a de Polignac number, because 865986971 - 2² = 865986967 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 865986971.

It is not an unprimeable number, because it can be changed into a prime (865986977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101750 + ... + 109931.

It is an arithmetic number, because the mean of its divisors is an integer number (216550686).

Almost surely, 2^865986971 is an apocalyptic number.

865986971 is a deficient number, since it is larger than the sum of its proper divisors (215773).

865986971 is a wasteful number, since it uses less digits than its factorization.

865986971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215772.

The product of its digits is 6531840, while the sum is 59.

The square root of 865986971 is about 29427.6565665702. The cubic root of 865986971 is about 953.1701925374.

The spelling of 865986971 in words is "eight hundred sixty-five million, nine hundred eighty-six thousand, nine hundred seventy-one".