21000222101 has 2 divisors, whose sum is σ = 21000222102. Its totient is φ = 21000222100.

The previous prime is 21000222071. The next prime is 21000222211. The reversal of 21000222101 is 10122200012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20549509201 + 450712900 = 143351^2 + 21230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000222101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000222601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500111050 + 10500111051.

It is an arithmetic number, because the mean of its divisors is an integer number (10500111051).

Almost surely, 2^21000222101 is an apocalyptic number.

It is an amenable number.

21000222101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000222101 is an equidigital number, since it uses as much as digits as its factorization.

21000222101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21000222101 its reverse (10122200012), we get a palindrome (31122422113).

The spelling of 21000222101 in words is "twenty-one billion, two hundred twenty-two thousand, one hundred one".