1212120111021 has 4 divisors (see below), whose sum is σ = 1616160148032. Its totient is φ = 808080074012.

The previous prime is 1212120110893. The next prime is 1212120111053. The reversal of 1212120111021 is 1201110212121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1212120111021 - 2⁷ = 1212120110893 is a prime.

It is a super-2 number, since 2×1212120111021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212120110021) 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, 202020018501 + ... + 202020018506.

It is an arithmetic number, because the mean of its divisors is an integer number (404040037008).

Almost surely, 2^{1212120111021} is an apocalyptic number.

It is an amenable number.

1212120111021 is a deficient number, since it is larger than the sum of its proper divisors (404040037011).

1212120111021 is an equidigital number, since it uses as much as digits as its factorization.

1212120111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404040037010.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1212120111021 its reverse (1201110212121), we get a palindrome (2413230323142).

The spelling of 1212120111021 in words is "one trillion, two hundred twelve billion, one hundred twenty million, one hundred eleven thousand, twenty-one".