866198831 has 4 divisors (see below), whose sum is σ = 866440632. Its totient is φ = 865957032.

The previous prime is 866198821. The next prime is 866198833. The reversal of 866198831 is 138891668.

It is a happy number.

866198831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 866198831 - 2²² = 862004527 is a prime.

It is a super-2 number, since 2×866198831² = 1500600829651533122, which contains 22 as substring.

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 866198831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866198833) 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, 115445 + ... + 122718.

It is an arithmetic number, because the mean of its divisors is an integer number (216610158).

Almost surely, 2^866198831 is an apocalyptic number.

866198831 is a deficient number, since it is larger than the sum of its proper divisors (241801).

866198831 is a wasteful number, since it uses less digits than its factorization.

866198831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241800.

The product of its digits is 497664, while the sum is 50.

The square root of 866198831 is about 29431.2560214477. The cubic root of 866198831 is about 953.2479158667.

The spelling of 866198831 in words is "eight hundred sixty-six million, one hundred ninety-eight thousand, eight hundred thirty-one".