21216566004203 has 4 divisors (see below), whose sum is σ = 21227179596000. Its totient is φ = 21205952412408.

The previous prime is 21216566004199. The next prime is 21216566004251. The reversal of 21216566004203 is 30240066561212.

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 21216566004203 - 2² = 21216566004199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21216566004703) 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, 5306792900 + ... + 5306796897.

It is an arithmetic number, because the mean of its divisors is an integer number (5306794899000).

Almost surely, 2^{21216566004203} is an apocalyptic number.

21216566004203 is a deficient number, since it is larger than the sum of its proper divisors (10613591797).

21216566004203 is a wasteful number, since it uses less digits than its factorization.

21216566004203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10613591796.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 21216566004203 in words is "twenty-one trillion, two hundred sixteen billion, five hundred sixty-six million, four thousand, two hundred three".