2172428666 has 8 divisors (see below), whose sum is σ = 3261837684. Its totient is φ = 1085149440.

The previous prime is 2172428659. The next prime is 2172428701. The reversal of 2172428666 is 6668242712.

It can be written as a sum of positive squares in 2 ways, for example, as 2021851225 + 150577441 = 44965^2 + 12271^2 .

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

It is a Curzon number.

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, 529895 + ... + 533978.

Almost surely, 2^2172428666 is an apocalyptic number.

2172428666 is a deficient number, since it is larger than the sum of its proper divisors (1089409018).

2172428666 is a wasteful number, since it uses less digits than its factorization.

2172428666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1064896.

The product of its digits is 387072, while the sum is 44.

The square root of 2172428666 is about 46609.3195187400. The cubic root of 2172428666 is about 1295.1354024280.

The spelling of 2172428666 in words is "two billion, one hundred seventy-two million, four hundred twenty-eight thousand, six hundred sixty-six".