1212122121111 has 54 divisors (see below), whose sum is σ = 1998398643696. Its totient is φ = 734618986200.

The previous prime is 1212122121107. The next prime is 1212122121137. The reversal of 1212122121111 is 1111212212121.

It is a happy number.

It is not a de Polignac number, because 1212122121111 - 2² = 1212122121107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212122121151) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 30466 + ... + 1557296.

Almost surely, 2^{1212122121111} is an apocalyptic number.

1212122121111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1212122121111 is a deficient number, since it is larger than the sum of its proper divisors (786276522585).

1212122121111 is an frugal number, since it uses more digits than its factorization.

1212122121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1526877 (or 1526845 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

Adding to 1212122121111 its reverse (1111212212121), we get a palindrome (2323334333232).

The spelling of 1212122121111 in words is "one trillion, two hundred twelve billion, one hundred twenty-two million, one hundred twenty-one thousand, one hundred eleven".