2161344666 has 32 divisors (see below), whose sum is σ = 4658387328. Its totient is φ = 664574400.

The previous prime is 2161344659. The next prime is 2161344719. The reversal of 2161344666 is 6664431612.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115891 + ... + 133241.

It is an arithmetic number, because the mean of its divisors is an integer number (145574604).

Almost surely, 2^2161344666 is an apocalyptic number.

2161344666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2161344666 is an abundant number, since it is smaller than the sum of its proper divisors (2497042662).

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

2161344666 is a wasteful number, since it uses less digits than its factorization.

2161344666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18966.

The product of its digits is 124416, while the sum is 39.

The square root of 2161344666 is about 46490.2642066057. The cubic root of 2161344666 is about 1292.9289986607.

The spelling of 2161344666 in words is "two billion, one hundred sixty-one million, three hundred forty-four thousand, six hundred sixty-six".