211212210421 has 2 divisors, whose sum is σ = 211212210422. Its totient is φ = 211212210420.

The previous prime is 211212210383. The next prime is 211212210499. The reversal of 211212210421 is 124012212112.

211212210421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129950156196 + 81262054225 = 360486^2 + 285065^2 .

It is a cyclic number.

It is not a de Polignac number, because 211212210421 - 2²⁷ = 211077992693 is a prime.

It is a super-2 number, since 2×211212210421² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211212210821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105606105210 + 105606105211.

It is an arithmetic number, because the mean of its divisors is an integer number (105606105211).

Almost surely, 2^211212210421 is an apocalyptic number.

It is an amenable number.

211212210421 is a deficient number, since it is larger than the sum of its proper divisors (1).

211212210421 is an equidigital number, since it uses as much as digits as its factorization.

211212210421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 211212210421 its reverse (124012212112), we get a palindrome (335224422533).

The spelling of 211212210421 in words is "two hundred eleven billion, two hundred twelve million, two hundred ten thousand, four hundred twenty-one".