1221111211222 has 64 divisors (see below), whose sum is σ = 2165685672960. Its totient is φ = 505556827776.

The previous prime is 1221111211171. The next prime is 1221111211231. The reversal of 1221111211222 is 2221121111221.

It is a happy number.

It is a super-2 number, since 2×1221111211222² (a number of 25 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1221111211222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138647943 + ... + 138656749.

It is an arithmetic number, because the mean of its divisors is an integer number (33838838640).

Almost surely, 2^{1221111211222} is an apocalyptic number.

1221111211222 is a deficient number, since it is larger than the sum of its proper divisors (944574461738).

1221111211222 is a wasteful number, since it uses less digits than its factorization.

1221111211222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11725.

The product of its digits is 64, while the sum is 19.

Adding to 1221111211222 its reverse (2221121111221), we get a palindrome (3442232322443).

The spelling of 1221111211222 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred eleven thousand, two hundred twenty-two".