21011121233213 has 2 divisors, whose sum is σ = 21011121233214. Its totient is φ = 21011121233212.

The previous prime is 21011121233203. The next prime is 21011121233233. The reversal of 21011121233213 is 31233212111012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10893518084089 + 10117603149124 = 3300533^2 + 3180818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011121233213 - 2¹⁴ = 21011121216829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011121233203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505560616606 + 10505560616607.

It is an arithmetic number, because the mean of its divisors is an integer number (10505560616607).

Almost surely, 2^{21011121233213} is an apocalyptic number.

It is an amenable number.

21011121233213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011121233213 is an equidigital number, since it uses as much as digits as its factorization.

21011121233213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21011121233213 its reverse (31233212111012), we get a palindrome (52244333344225).

The spelling of 21011121233213 in words is "twenty-one trillion, eleven billion, one hundred twenty-one million, two hundred thirty-three thousand, two hundred thirteen".