12212021 has 2 divisors, whose sum is σ = 12212022. Its totient is φ = 12212020.

The previous prime is 12211981. The next prime is 12212029. The reversal of 12212021 is 12021221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9991921 + 2220100 = 3161^2 + 1490^2 .

It is a cyclic number.

It is not a de Polignac number, because 12212021 - 2¹⁴ = 12195637 is a prime.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 12211993 and 12212011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12212029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6106010 + 6106011.

It is an arithmetic number, because the mean of its divisors is an integer number (6106011).

Almost surely, 2^12212021 is an apocalyptic number.

It is an amenable number.

12212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12212021 is an equidigital number, since it uses as much as digits as its factorization.

12212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 12212021 is about 3494.5702167792. The cubic root of 12212021 is about 230.2833370142.

Adding to 12212021 its reverse (12021221), we get a palindrome (24233242).

The spelling of 12212021 in words is "twelve million, two hundred twelve thousand, twenty-one".