21000111227 has 2 divisors, whose sum is σ = 21000111228. Its totient is φ = 21000111226.

The previous prime is 21000111179. The next prime is 21000111229. The reversal of 21000111227 is 72211100012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000111227 - 2¹⁰ = 21000110203 is a prime.

It is a super-3 number, since 3×21000111227³ (a number of 32 digits) contains 333 as substring.

Together with 21000111229, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21000111229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500055613 + 10500055614.

It is an arithmetic number, because the mean of its divisors is an integer number (10500055614).

Almost surely, 2^21000111227 is an apocalyptic number.

21000111227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000111227 is an equidigital number, since it uses as much as digits as its factorization.

21000111227 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 17.

Adding to 21000111227 its reverse (72211100012), we get a palindrome (93211211239).

The spelling of 21000111227 in words is "twenty-one billion, one hundred eleven thousand, two hundred twenty-seven".