1213100221221 has 20 divisors (see below), whose sum is σ = 2071042353952. Its totient is φ = 693200126088.

The previous prime is 1213100221183. The next prime is 1213100221243. The reversal of 1213100221221 is 1221220013121.

1213100221221 is a `hidden beast` number, since 1 + 213 + 10 + 0 + 221 + 221 = 666.

It is not a de Polignac number, because 1213100221221 - 2⁷ = 1213100221093 is a prime.

It is a super-2 number, since 2×1213100221221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1213100221194 and 1213100221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213100221271) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1069752715 + ... + 1069753848.

Almost surely, 2^{1213100221221} is an apocalyptic number.

It is an amenable number.

1213100221221 is a deficient number, since it is larger than the sum of its proper divisors (857942132731).

1213100221221 is an equidigital number, since it uses as much as digits as its factorization.

1213100221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2139506582 (or 2139506573 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 1213100221221 its reverse (1221220013121), we get a palindrome (2434320234342).

The spelling of 1213100221221 in words is "one trillion, two hundred thirteen billion, one hundred million, two hundred twenty-one thousand, two hundred twenty-one".