866840987 has 4 divisors (see below), whose sum is σ = 869069760. Its totient is φ = 864612216.

The previous prime is 866840969. The next prime is 866840993. The reversal of 866840987 is 789048668.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866840987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (866840957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1113803 + ... + 1114580.

It is an arithmetic number, because the mean of its divisors is an integer number (217267440).

Almost surely, 2^866840987 is an apocalyptic number.

866840987 is a deficient number, since it is larger than the sum of its proper divisors (2228773).

866840987 is a wasteful number, since it uses less digits than its factorization.

866840987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2228772.

The product of its (nonzero) digits is 4644864, while the sum is 56.

The square root of 866840987 is about 29442.1634225476. The cubic root of 866840987 is about 953.4834209419.

The spelling of 866840987 in words is "eight hundred sixty-six million, eight hundred forty thousand, nine hundred eighty-seven".