1221111001111 has 16 divisors (see below), whose sum is σ = 1296003237120. Its totient is φ = 1148041699200.

The previous prime is 1221111001091. The next prime is 1221111001151. The reversal of 1221111001111 is 1111001111221.

It is a cyclic number.

It is not a de Polignac number, because 1221111001111 - 2¹⁷ = 1221110870039 is a prime.

It is a super-2 number, since 2×1221111001111² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221111001091 and 1221111001100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221111001151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8987836 + ... + 9122686.

It is an arithmetic number, because the mean of its divisors is an integer number (81000202320).

Almost surely, 2^{1221111001111} is an apocalyptic number.

1221111001111 is a deficient number, since it is larger than the sum of its proper divisors (74892236009).

1221111001111 is a wasteful number, since it uses less digits than its factorization.

1221111001111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141606.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 1221111001111 its reverse (1111001111221), we get a palindrome (2332112112332).

The spelling of 1221111001111 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, one thousand, one hundred eleven".