21201101122121 has 2 divisors, whose sum is σ = 21201101122122. Its totient is φ = 21201101122120.

The previous prime is 21201101122109. The next prime is 21201101122133. The reversal of 21201101122121 is 12122110110212.

It is a balanced prime because it is at equal distance from previous prime (21201101122109) and next prime (21201101122133).

It can be written as a sum of positive squares in only one way, i.e., 14423201288521 + 6777899833600 = 3797789^2 + 2603440^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201101122121 - 2⁶ = 21201101122057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201101122121.

It is not a weakly prime, because it can be changed into another prime (21201101128121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600550561060 + 10600550561061.

It is an arithmetic number, because the mean of its divisors is an integer number (10600550561061).

Almost surely, 2^{21201101122121} is an apocalyptic number.

It is an amenable number.

21201101122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201101122121 is an equidigital number, since it uses as much as digits as its factorization.

21201101122121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21201101122121 its reverse (12122110110212), we get a palindrome (33323211232333).

The spelling of 21201101122121 in words is "twenty-one trillion, two hundred one billion, one hundred one million, one hundred twenty-two thousand, one hundred twenty-one".