21111201211201 has 2 divisors, whose sum is σ = 21111201211202. Its totient is φ = 21111201211200.

The previous prime is 21111201211157. The next prime is 21111201211223. The reversal of 21111201211201 is 10211210211112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14605390890000 + 6505810321201 = 3821700^2 + 2550649^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111201211201 - 2¹⁵ = 21111201178433 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111201211601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555600605600 + 10555600605601.

It is an arithmetic number, because the mean of its divisors is an integer number (10555600605601).

Almost surely, 2^{21111201211201} is an apocalyptic number.

It is an amenable number.

21111201211201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111201211201 is an equidigital number, since it uses as much as digits as its factorization.

21111201211201 is an evil number, because the sum of its binary digits is even.

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

Adding to 21111201211201 its reverse (10211210211112), we get a palindrome (31322411422313).

The spelling of 21111201211201 in words is "twenty-one trillion, one hundred eleven billion, two hundred one million, two hundred eleven thousand, two hundred one".