12012120021 has 16 divisors (see below), whose sum is σ = 17474941440. Its totient is φ = 7278919920.

The previous prime is 12012120013. The next prime is 12012120053. The reversal of 12012120021 is 12002121021.

It is not a de Polignac number, because 12012120021 - 2³ = 12012120013 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12012119979 and 12012120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12012120091) 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, 213016 + ... + 263438.

It is an arithmetic number, because the mean of its divisors is an integer number (1092183840).

Almost surely, 2^12012120021 is an apocalyptic number.

12012120021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12012120021 is a deficient number, since it is larger than the sum of its proper divisors (5462821419).

12012120021 is a wasteful number, since it uses less digits than its factorization.

12012120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57656.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 12012120021 its reverse (12002121021), we get a palindrome (24014241042).

The spelling of 12012120021 in words is "twelve billion, twelve million, one hundred twenty thousand, twenty-one".