865842987 has 4 divisors (see below), whose sum is σ = 1154457320. Its totient is φ = 577228656.

The previous prime is 865842983. The next prime is 865843001. The reversal of 865842987 is 789248568.

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

It is not a de Polignac number, because 865842987 - 2² = 865842983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (865842983) 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, 144307162 + ... + 144307167.

It is an arithmetic number, because the mean of its divisors is an integer number (288614330).

Almost surely, 2^865842987 is an apocalyptic number.

865842987 is a deficient number, since it is larger than the sum of its proper divisors (288614333).

865842987 is a wasteful number, since it uses less digits than its factorization.

865842987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288614332.

The product of its digits is 7741440, while the sum is 57.

The square root of 865842987 is about 29425.2100587235. The cubic root of 865842987 is about 953.1173630806.

The spelling of 865842987 in words is "eight hundred sixty-five million, eight hundred forty-two thousand, nine hundred eighty-seven".