21666333465123 has 4 divisors (see below), whose sum is σ = 28888444620168. Its totient is φ = 14444222310080.

The previous prime is 21666333465113. The next prime is 21666333465151. The reversal of 21666333465123 is 32156433366612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21666333465123 - 2¹⁰ = 21666333464099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21666333465103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3611055577518 + ... + 3611055577523.

It is an arithmetic number, because the mean of its divisors is an integer number (7222111155042).

Almost surely, 2^{21666333465123} is an apocalyptic number.

21666333465123 is a deficient number, since it is larger than the sum of its proper divisors (7222111155045).

21666333465123 is an equidigital number, since it uses as much as digits as its factorization.

21666333465123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7222111155044.

The product of its digits is 8398080, while the sum is 51.

The spelling of 21666333465123 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred thirty-three million, four hundred sixty-five thousand, one hundred twenty-three".