21211221122101 has 2 divisors, whose sum is σ = 21211221122102. Its totient is φ = 21211221122100.

The previous prime is 21211221122057. The next prime is 21211221122137. The reversal of 21211221122101 is 10122112211212.

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., 20728661659876 + 482559462225 = 4552874^2 + 694665^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211221122101 - 2¹¹ = 21211221120053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211221126101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605610561050 + 10605610561051.

It is an arithmetic number, because the mean of its divisors is an integer number (10605610561051).

Almost surely, 2^{21211221122101} is an apocalyptic number.

It is an amenable number.

21211221122101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211221122101 is an equidigital number, since it uses as much as digits as its factorization.

21211221122101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21211221122101 its reverse (10122112211212), we get a palindrome (31333333333313).

The spelling of 21211221122101 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twenty-two thousand, one hundred one".