1221412221 has 12 divisors (see below), whose sum is σ = 1766892348. Its totient is φ = 813060864.

The previous prime is 1221412201. The next prime is 1221412229. The reversal of 1221412221 is 1222141221.

1221412221 is a `hidden beast` number, since 12 + 21 + 412 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 119902500 + 1101509721 = 10950^2 + 33189^2 .

It is not a de Polignac number, because 1221412221 - 2¹¹ = 1221410173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221412194 and 1221412203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221412229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 94770 + ... + 106883.

It is an arithmetic number, because the mean of its divisors is an integer number (147241029).

Almost surely, 2^1221412221 is an apocalyptic number.

It is an amenable number.

1221412221 is a deficient number, since it is larger than the sum of its proper divisors (545480127).

1221412221 is a wasteful number, since it uses less digits than its factorization.

1221412221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202332 (or 202329 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 1221412221 is about 34948.7084310708. The cubic root of 1221412221 is about 1068.9418662818.

Adding to 1221412221 its reverse (1222141221), we get a palindrome (2443553442).

Subtracting 1221412221 from its reverse (1222141221), we obtain a cube (729000 = 90³).

The spelling of 1221412221 in words is "one billion, two hundred twenty-one million, four hundred twelve thousand, two hundred twenty-one".