2164621666 has 8 divisors (see below), whose sum is σ = 3247593984. Its totient is φ = 1082090340.

The previous prime is 2164621651. The next prime is 2164621673. The reversal of 2164621666 is 6661264612.

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, 97690 + ... + 117781.

It is an arithmetic number, because the mean of its divisors is an integer number (405949248).

Almost surely, 2^2164621666 is an apocalyptic number.

2164621666 is a deficient number, since it is larger than the sum of its proper divisors (1082972318).

2164621666 is a wasteful number, since it uses less digits than its factorization.

2164621666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220496.

The product of its digits is 124416, while the sum is 40.

The square root of 2164621666 is about 46525.4947958643. The cubic root of 2164621666 is about 1293.5821088708.

The spelling of 2164621666 in words is "two billion, one hundred sixty-four million, six hundred twenty-one thousand, six hundred sixty-six".