2172193666 has 12 divisors (see below), whose sum is σ = 3450386322. Its totient is φ = 1022080896.

The previous prime is 2172193657. The next prime is 2172193679. The reversal of 2172193666 is 6663912712.

It can be written as a sum of positive squares in 3 ways, for example, as 1209022441 + 963171225 = 34771^2 + 31035^2 .

It is a super-2 number, since 2×2172193666² = 9436850645221039112, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 267766 + ... + 275758.

Almost surely, 2^2172193666 is an apocalyptic number.

2172193666 is a deficient number, since it is larger than the sum of its proper divisors (1278192656).

2172193666 is an frugal number, since it uses more digits than its factorization.

2172193666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16005 (or 8012 counting only the distinct ones).

The product of its digits is 163296, while the sum is 43.

The square root of 2172193666 is about 46606.7984954985. The cubic root of 2172193666 is about 1295.0887008110.

The spelling of 2172193666 in words is "two billion, one hundred seventy-two million, one hundred ninety-three thousand, six hundred sixty-six".