805865887 has 4 divisors (see below), whose sum is σ = 805941216. Its totient is φ = 805790560.

The previous prime is 805865873. The next prime is 805865917. The reversal of 805865887 is 788568508.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-805865887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805865087) 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, 18298 + ... + 44119.

It is an arithmetic number, because the mean of its divisors is an integer number (201485304).

Almost surely, 2^805865887 is an apocalyptic number.

805865887 is a deficient number, since it is larger than the sum of its proper divisors (75329).

805865887 is a wasteful number, since it uses less digits than its factorization.

805865887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75328.

The product of its (nonzero) digits is 4300800, while the sum is 55.

The square root of 805865887 is about 28387.7770704224. Note that the first 3 decimals coincide. The cubic root of 805865887 is about 930.5811633248.

The spelling of 805865887 in words is "eight hundred five million, eight hundred sixty-five thousand, eight hundred eighty-seven".