861099818 has 8 divisors (see below), whose sum is σ = 1292434212. Its totient is φ = 430288416.

The previous prime is 861099787. The next prime is 861099821. The reversal of 861099818 is 818990168.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 849897409 + 11202409 = 29153^2 + 3347^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126605 + ... + 133232.

Almost surely, 2^861099818 is an apocalyptic number.

861099818 is a deficient number, since it is larger than the sum of its proper divisors (431334394).

861099818 is a wasteful number, since it uses less digits than its factorization.

861099818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261496.

The product of its (nonzero) digits is 248832, while the sum is 50.

The square root of 861099818 is about 29344.5023471178. The cubic root of 861099818 is about 951.3737532385.

The spelling of 861099818 in words is "eight hundred sixty-one million, ninety-nine thousand, eight hundred eighteen".