1221102211211 has 4 divisors (see below), whose sum is σ = 1221852736632. Its totient is φ = 1220351685792.

The previous prime is 1221102211193. The next prime is 1221102211271. The reversal of 1221102211211 is 1121122011221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221102211211 is a prime.

It is a super-2 number, since 2×1221102211211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221102211211.

It is not an unprimeable number, because it can be changed into a prime (1221102211271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375260270 + ... + 375263523.

It is an arithmetic number, because the mean of its divisors is an integer number (305463184158).

Almost surely, 2^{1221102211211} is an apocalyptic number.

1221102211211 is a deficient number, since it is larger than the sum of its proper divisors (750525421).

1221102211211 is an equidigital number, since it uses as much as digits as its factorization.

1221102211211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750525420.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221102211211 its reverse (1121122011221), we get a palindrome (2342224222432).

The spelling of 1221102211211 in words is "one trillion, two hundred twenty-one billion, one hundred two million, two hundred eleven thousand, two hundred eleven".