21121211202101 has 2 divisors, whose sum is σ = 21121211202102. Its totient is φ = 21121211202100.

The previous prime is 21121211202067. The next prime is 21121211202163. The reversal of 21121211202101 is 10120211212112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18687689201476 + 2433522000625 = 4322926^2 + 1559975^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121211202101 - 2²⁶ = 21121144093237 is a prime.

It is a super-2 number, since 2×21121211202101² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121211202101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121211202181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560605601050 + 10560605601051.

It is an arithmetic number, because the mean of its divisors is an integer number (10560605601051).

Almost surely, 2^{21121211202101} is an apocalyptic number.

It is an amenable number.

21121211202101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121211202101 is an equidigital number, since it uses as much as digits as its factorization.

21121211202101 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21121211202101 its reverse (10120211212112), we get a palindrome (31241422414213).

The spelling of 21121211202101 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, two hundred two thousand, one hundred one".