1211001212111 has 16 divisors (see below), whose sum is σ = 1225432574496. Its totient is φ = 1196619600000.

The previous prime is 1211001212077. The next prime is 1211001212117. The reversal of 1211001212111 is 1112121001121.

It is a cyclic number.

It is not a de Polignac number, because 1211001212111 - 2¹⁴ = 1211001195727 is a prime.

It is a super-2 number, since 2×1211001212111² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211001212117) 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, 225048641 + ... + 225054021.

It is an arithmetic number, because the mean of its divisors is an integer number (76589535906).

Almost surely, 2^{1211001212111} is an apocalyptic number.

1211001212111 is a deficient number, since it is larger than the sum of its proper divisors (14431362385).

1211001212111 is a wasteful number, since it uses less digits than its factorization.

1211001212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9514.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 1211001212111 its reverse (1112121001121), we get a palindrome (2323122213232).

The spelling of 1211001212111 in words is "one trillion, two hundred eleven billion, one million, two hundred twelve thousand, one hundred eleven".