1212221101221 has 64 divisors (see below), whose sum is σ = 2016184289280. Its totient is φ = 714769920000.

The previous prime is 1212221101213. The next prime is 1212221101291. The reversal of 1212221101221 is 1221011222121.

1212221101221 is a `hidden beast` number, since 1 + 212 + 221 + 10 + 1 + 221 = 666.

It is not a de Polignac number, because 1212221101221 - 2³ = 1212221101213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212221101194 and 1212221101203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212221101291) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 547461 + ... + 1650501.

It is an arithmetic number, because the mean of its divisors is an integer number (31502879520).

Almost surely, 2^{1212221101221} is an apocalyptic number.

It is an amenable number.

1212221101221 is a deficient number, since it is larger than the sum of its proper divisors (803963188059).

1212221101221 is a wasteful number, since it uses less digits than its factorization.

1212221101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103195 (or 1103189 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212221101221 its reverse (1221011222121), we get a palindrome (2433232323342).

The spelling of 1212221101221 in words is "one trillion, two hundred twelve billion, two hundred twenty-one million, one hundred one thousand, two hundred twenty-one".