21221201212231 has 2 divisors, whose sum is σ = 21221201212232. Its totient is φ = 21221201212230.

The previous prime is 21221201212171. The next prime is 21221201212319. The reversal of 21221201212231 is 13221210212212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221201212231 - 2²⁹ = 21220664341319 is a prime.

It is a super-2 number, since 2×21221201212231² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221201212531) 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, 10610600606115 + 10610600606116.

It is an arithmetic number, because the mean of its divisors is an integer number (10610600606116).

Almost surely, 2^{21221201212231} is an apocalyptic number.

21221201212231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221201212231 is an equidigital number, since it uses as much as digits as its factorization.

21221201212231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

Adding to 21221201212231 its reverse (13221210212212), we get a palindrome (34442411424443).

The spelling of 21221201212231 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, two hundred twelve thousand, two hundred thirty-one".