1221122111011 has 4 divisors (see below), whose sum is σ = 1332133212024. Its totient is φ = 1110111010000.

The previous prime is 1221122110997. The next prime is 1221122111107. The reversal of 1221122111011 is 1101112211221.

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 1221122111011 - 2⁵ = 1221122110979 is a prime.

It is a super-2 number, since 2×1221122111011² (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 (1221122111311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55505550490 + ... + 55505550511.

It is an arithmetic number, because the mean of its divisors is an integer number (333033303006).

Almost surely, 2^{1221122111011} is an apocalyptic number.

1221122111011 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221122111011 is a deficient number, since it is larger than the sum of its proper divisors (111011101013).

1221122111011 is a wasteful number, since it uses less digits than its factorization.

1221122111011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111011101012.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1221122111011 its reverse (1101112211221), we get a palindrome (2322234322232).

It can be divided in two parts, 12211221 and 11011, that multiplied together give a palindrome (134457754431).

The spelling of 1221122111011 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred eleven thousand, eleven".