21127111189 has 2 divisors, whose sum is σ = 21127111190. Its totient is φ = 21127111188.

The previous prime is 21127111171. The next prime is 21127111193. The reversal of 21127111189 is 98111172112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15195492900 + 5931618289 = 123270^2 + 77017^2 .

It is a cyclic number.

It is not a de Polignac number, because 21127111189 - 2²¹ = 21125014037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21127111589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563555594 + 10563555595.

It is an arithmetic number, because the mean of its divisors is an integer number (10563555595).

Almost surely, 2^21127111189 is an apocalyptic number.

It is an amenable number.

21127111189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127111189 is an equidigital number, since it uses as much as digits as its factorization.

21127111189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 34.

The spelling of 21127111189 in words is "twenty-one billion, one hundred twenty-seven million, one hundred eleven thousand, one hundred eighty-nine".