2181398668 has 12 divisors (see below), whose sum is σ = 3818815000. Its totient is φ = 1090308672.

The previous prime is 2181398627. The next prime is 2181398671. The reversal of 2181398668 is 8668931812.

It is a hoax number, since the sum of its digits (52) coincides with the sum of the digits of its distinct prime factors.

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, 84918 + ... + 107581.

Almost surely, 2^2181398668 is an apocalyptic number.

It is an amenable number.

2181398668 is a deficient number, since it is larger than the sum of its proper divisors (1637416332).

2181398668 is a wasteful number, since it uses less digits than its factorization.

2181398668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195336 (or 195334 counting only the distinct ones).

The product of its digits is 995328, while the sum is 52.

The square root of 2181398668 is about 46705.4458066723. The cubic root of 2181398668 is about 1296.9155014268.

The spelling of 2181398668 in words is "two billion, one hundred eighty-one million, three hundred ninety-eight thousand, six hundred sixty-eight".