1212020221 has 2 divisors, whose sum is σ = 1212020222. Its totient is φ = 1212020220.

The previous prime is 1212020209. The next prime is 1212020263. The reversal of 1212020221 is 1220202121.

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., 1212014596 + 5625 = 34814^2 + 75^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212020221 - 2⁷ = 1212020093 is a prime.

It is a super-2 number, since 2×1212020221² = 2937986032225777682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212020521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606010110 + 606010111.

It is an arithmetic number, because the mean of its divisors is an integer number (606010111).

Almost surely, 2^1212020221 is an apocalyptic number.

It is an amenable number.

1212020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212020221 is an equidigital number, since it uses as much as digits as its factorization.

1212020221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1212020221 is about 34814.0807863715. The cubic root of 1212020221 is about 1066.1949516551.

Adding to 1212020221 its reverse (1220202121), we get a palindrome (2432222342).

The spelling of 1212020221 in words is "one billion, two hundred twelve million, twenty thousand, two hundred twenty-one".