1211222123111 has 144 divisors (see below), whose sum is σ = 1788451297920. Its totient is φ = 809512704000.

The previous prime is 1211222123081. The next prime is 1211222123141. The reversal of 1211222123111 is 1113212221121.

It is an interprime number because it is at equal distance from previous prime (1211222123081) and next prime (1211222123141).

It is not a de Polignac number, because 1211222123111 - 2¹⁸ = 1211221860967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211222123141) 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 143 ways as a sum of consecutive naturals, for example, 103508561 + ... + 103520261.

It is an arithmetic number, because the mean of its divisors is an integer number (12419800680).

Almost surely, 2^{1211222123111} is an apocalyptic number.

1211222123111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1211222123111 is a deficient number, since it is larger than the sum of its proper divisors (577229174809).

1211222123111 is a wasteful number, since it uses less digits than its factorization.

1211222123111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11846 (or 11828 counting only the distinct ones).

The product of its digits is 96, while the sum is 20.

Adding to 1211222123111 its reverse (1113212221121), we get a palindrome (2324434344232).

The spelling of 1211222123111 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, one hundred twenty-three thousand, one hundred eleven".