1221211123111 has 32 divisors (see below), whose sum is σ = 1442079936000. Its totient is φ = 1012468101120.

The previous prime is 1221211123091. The next prime is 1221211123117. The reversal of 1221211123111 is 1113211121221.

It is not a de Polignac number, because 1221211123111 - 2¹⁵ = 1221211090343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221211123117) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12937815 + ... + 13031863.

It is an arithmetic number, because the mean of its divisors is an integer number (45064998000).

Almost surely, 2^{1221211123111} is an apocalyptic number.

1221211123111 is a deficient number, since it is larger than the sum of its proper divisors (220868812889).

1221211123111 is a wasteful number, since it uses less digits than its factorization.

1221211123111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94519.

The product of its digits is 48, while the sum is 19.

Adding to 1221211123111 its reverse (1113211121221), we get a palindrome (2334422244332).

The spelling of 1221211123111 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twenty-three thousand, one hundred eleven".