21213233321237 has 2 divisors, whose sum is σ = 21213233321238. Its totient is φ = 21213233321236.

The previous prime is 21213233321209. The next prime is 21213233321321. The reversal of 21213233321237 is 73212333231212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20323741010596 + 889492310641 = 4508186^2 + 943129^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213233321237 - 2¹⁸ = 21213233059093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21213233321197 and 21213233321206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213233321437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606616660618 + 10606616660619.

It is an arithmetic number, because the mean of its divisors is an integer number (10606616660619).

Almost surely, 2^{21213233321237} is an apocalyptic number.

It is an amenable number.

21213233321237 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213233321237 is an equidigital number, since it uses as much as digits as its factorization.

21213233321237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 35.

Adding to 21213233321237 its reverse (73212333231212), we get a palindrome (94425566552449).

The spelling of 21213233321237 in words is "twenty-one trillion, two hundred thirteen billion, two hundred thirty-three million, three hundred twenty-one thousand, two hundred thirty-seven".