1212220111221 has 48 divisors (see below), whose sum is σ = 2088429557760. Its totient is φ = 662485111200.

The previous prime is 1212220111217. The next prime is 1212220111229. The reversal of 1212220111221 is 1221110222121.

1212220111221 is a `hidden beast` number, since 1 + 212 + 220 + 1 + 11 + 221 = 666.

It is not a de Polignac number, because 1212220111221 - 2² = 1212220111217 is a prime.

It is a super-2 number, since 2×1212220111221² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1212220111194 and 1212220111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212220111229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10740360 + ... + 10852638.

It is an arithmetic number, because the mean of its divisors is an integer number (43508949120).

Almost surely, 2^{1212220111221} is an apocalyptic number.

It is an amenable number.

1212220111221 is a deficient number, since it is larger than the sum of its proper divisors (876209446539).

1212220111221 is a wasteful number, since it uses less digits than its factorization.

1212220111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119766 (or 119763 counting only the distinct ones).

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

Adding to 1212220111221 its reverse (1221110222121), we get a palindrome (2433330333342).

The spelling of 1212220111221 in words is "one trillion, two hundred twelve billion, two hundred twenty million, one hundred eleven thousand, two hundred twenty-one".