21216112201 has 2 divisors, whose sum is σ = 21216112202. Its totient is φ = 21216112200.

The previous prime is 21216112199. The next prime is 21216112223. The reversal of 21216112201 is 10221161212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19628010000 + 1588102201 = 140100^2 + 39851^2 .

It is a cyclic number.

It is not a de Polignac number, because 21216112201 - 2¹ = 21216112199 is a prime.

Together with 21216112199, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21216112501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608056100 + 10608056101.

It is an arithmetic number, because the mean of its divisors is an integer number (10608056101).

Almost surely, 2^21216112201 is an apocalyptic number.

It is an amenable number.

21216112201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216112201 is an equidigital number, since it uses as much as digits as its factorization.

21216112201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 21216112201 its reverse (10221161212), we get a palindrome (31437273413).

The spelling of 21216112201 in words is "twenty-one billion, two hundred sixteen million, one hundred twelve thousand, two hundred one".