865206855 has 12 divisors (see below), whose sum is σ = 1499691960. Its totient is φ = 461443632.

The previous prime is 865206817. The next prime is 865206863. The reversal of 865206855 is 558602568.

It is not a de Polignac number, because 865206855 - 2⁶ = 865206791 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 19226819 = 865206855 / (8 + 6 + 5 + 2 + 0 + 6 + 8 + 5 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 865206855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9613365 + ... + 9613454.

It is an arithmetic number, because the mean of its divisors is an integer number (124974330).

Almost surely, 2^865206855 is an apocalyptic number.

865206855 is a deficient number, since it is larger than the sum of its proper divisors (634485105).

865206855 is a wasteful number, since it uses less digits than its factorization.

865206855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19226830 (or 19226827 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 45.

The square root of 865206855 is about 29414.3987699902. The cubic root of 865206855 is about 952.8838884944.

The spelling of 865206855 in words is "eight hundred sixty-five million, two hundred six thousand, eight hundred fifty-five".