212211421 has 2 divisors, whose sum is σ = 212211422. Its totient is φ = 212211420.

The previous prime is 212211397. The next prime is 212211427. The reversal of 212211421 is 124112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147987225 + 64224196 = 12165^2 + 8014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212211421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212211395 and 212211404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212211427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106105710 + 106105711.

It is an arithmetic number, because the mean of its divisors is an integer number (106105711).

Almost surely, 2^212211421 is an apocalyptic number.

It is an amenable number.

212211421 is a deficient number, since it is larger than the sum of its proper divisors (1).

212211421 is an equidigital number, since it uses as much as digits as its factorization.

212211421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 16.

The square root of 212211421 is about 14567.4781963111. The cubic root of 212211421 is about 596.4713448180.

Adding to 212211421 its reverse (124112212), we get a palindrome (336323633).

The spelling of 212211421 in words is "two hundred twelve million, two hundred eleven thousand, four hundred twenty-one".