21212210220137 has 2 divisors, whose sum is σ = 21212210220138. Its totient is φ = 21212210220136.

The previous prime is 21212210220121. The next prime is 21212210220239. The reversal of 21212210220137 is 73102201221212.

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., 14785686086656 + 6426524133481 = 3845216^2 + 2535059^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212210220137 - 2⁴ = 21212210220121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212210220037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606105110068 + 10606105110069.

It is an arithmetic number, because the mean of its divisors is an integer number (10606105110069).

Almost surely, 2^{21212210220137} is an apocalyptic number.

It is an amenable number.

21212210220137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212210220137 is an equidigital number, since it uses as much as digits as its factorization.

21212210220137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21212210220137 its reverse (73102201221212), we get a palindrome (94314411441349).

The spelling of 21212210220137 in words is "twenty-one trillion, two hundred twelve billion, two hundred ten million, two hundred twenty thousand, one hundred thirty-seven".