1221122122211 has 4 divisors (see below), whose sum is σ = 1221173824800. Its totient is φ = 1221070419624.

The previous prime is 1221122122193. The next prime is 1221122122217. The reversal of 1221122122211 is 1122212211221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221122122211 - 2⁶ = 1221122122147 is a prime.

It is a super-2 number, since 2×1221122122211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221122122217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25815851 + ... + 25863108.

It is an arithmetic number, because the mean of its divisors is an integer number (305293456200).

Almost surely, 2^{1221122122211} is an apocalyptic number.

1221122122211 is a deficient number, since it is larger than the sum of its proper divisors (51702589).

1221122122211 is an equidigital number, since it uses as much as digits as its factorization.

1221122122211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51702588.

The product of its digits is 128, while the sum is 20.

Adding to 1221122122211 its reverse (1122212211221), we get a palindrome (2343334333432).

The spelling of 1221122122211 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred eleven".