2123543666 has 8 divisors (see below), whose sum is σ = 3186098604. Its totient is φ = 1061510800.

The previous prime is 2123543641. The next prime is 2123543677. The reversal of 2123543666 is 6663453212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2082005641 + 41538025 = 45629^2 + 6445^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120185 + ... + 136716.

Almost surely, 2^2123543666 is an apocalyptic number.

2123543666 is a deficient number, since it is larger than the sum of its proper divisors (1062554938).

2123543666 is a wasteful number, since it uses less digits than its factorization.

2123543666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261036.

The product of its digits is 155520, while the sum is 38.

The square root of 2123543666 is about 46081.9234190588. The cubic root of 2123543666 is about 1285.3470305782.

Adding to 2123543666 its reverse (6663453212), we get a palindrome (8786996878).

The spelling of 2123543666 in words is "two billion, one hundred twenty-three million, five hundred forty-three thousand, six hundred sixty-six".