18215689866 has 32 divisors (see below), whose sum is σ = 39775838400. Its totient is φ = 5515390080.

The previous prime is 18215689853. The next prime is 18215689967. The reversal of 18215689866 is 66898651281.

It is a super-2 number, since 2×18215689866² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31171 + ... + 193398.

It is an arithmetic number, because the mean of its divisors is an integer number (1242994950).

Almost surely, 2^18215689866 is an apocalyptic number.

18215689866 is an abundant number, since it is smaller than the sum of its proper divisors (21560148534).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18215689866 is a wasteful number, since it uses less digits than its factorization.

18215689866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225814.

The product of its digits is 9953280, while the sum is 60.

The spelling of 18215689866 in words is "eighteen billion, two hundred fifteen million, six hundred eighty-nine thousand, eight hundred sixty-six".