21212320221013 has 2 divisors, whose sum is σ = 21212320221014. Its totient is φ = 21212320221012.

The previous prime is 21212320220921. The next prime is 21212320221017. The reversal of 21212320221013 is 31012202321212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20426576258929 + 785743962084 = 4519577^2 + 886422^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212320221013 - 2²⁵ = 21212286666581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212320221017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606160110506 + 10606160110507.

It is an arithmetic number, because the mean of its divisors is an integer number (10606160110507).

Almost surely, 2^{21212320221013} is an apocalyptic number.

It is an amenable number.

21212320221013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212320221013 is an equidigital number, since it uses as much as digits as its factorization.

21212320221013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 21212320221013 its reverse (31012202321212), we get a palindrome (52224522542225).

The spelling of 21212320221013 in words is "twenty-one trillion, two hundred twelve billion, three hundred twenty million, two hundred twenty-one thousand, thirteen".