12121201111 has 4 divisors (see below), whose sum is σ = 12195564472. Its totient is φ = 12046837752.

The previous prime is 12121201109. The next prime is 12121201129. The reversal of 12121201111 is 11110212121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11110212121 = 14827 ⋅749323.

It is a cyclic number.

It is not a de Polignac number, because 12121201111 - 2¹ = 12121201109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121201091 and 12121201100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121201711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37181436 + ... + 37181761.

It is an arithmetic number, because the mean of its divisors is an integer number (3048891118).

Almost surely, 2^12121201111 is an apocalyptic number.

12121201111 is a deficient number, since it is larger than the sum of its proper divisors (74363361).

12121201111 is an equidigital number, since it uses as much as digits as its factorization.

12121201111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74363360.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 12121201111 its reverse (11110212121), we get a palindrome (23231413232).

The spelling of 12121201111 in words is "twelve billion, one hundred twenty-one million, two hundred one thousand, one hundred eleven".