12121011211111 has 4 divisors (see below), whose sum is σ = 13222921321224. Its totient is φ = 11019101101000.

The previous prime is 12121011211039. The next prime is 12121011211117. The reversal of 12121011211111 is 11111211012121.

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 12121011211111 - 2³⁷ = 11983572257639 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 (12121011211117) 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 3 ways as a sum of consecutive naturals, for example, 550955055040 + ... + 550955055061.

It is an arithmetic number, because the mean of its divisors is an integer number (3305730330306).

Almost surely, 2^{12121011211111} is an apocalyptic number.

12121011211111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12121011211111 is a deficient number, since it is larger than the sum of its proper divisors (1101910110113).

12121011211111 is a wasteful number, since it uses less digits than its factorization.

12121011211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101910110112.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 12121011211111 its reverse (11111211012121), we get a palindrome (23232222223232).

The spelling of 12121011211111 in words is "twelve trillion, one hundred twenty-one billion, eleven million, two hundred eleven thousand, one hundred eleven".