21011222101 has 2 divisors, whose sum is σ = 21011222102. Its totient is φ = 21011222100.

The previous prime is 21011222093. The next prime is 21011222149. The reversal of 21011222101 is 10122211012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20844140625 + 167081476 = 144375^2 + 12926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011222101 - 2³ = 21011222093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011222161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505611050 + 10505611051.

It is an arithmetic number, because the mean of its divisors is an integer number (10505611051).

Almost surely, 2^21011222101 is an apocalyptic number.

It is an amenable number.

21011222101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011222101 is an equidigital number, since it uses as much as digits as its factorization.

21011222101 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 13.

Adding to 21011222101 its reverse (10122211012), we get a palindrome (31133433113).

The spelling of 21011222101 in words is "twenty-one billion, eleven million, two hundred twenty-two thousand, one hundred one".