12120120021 has 4 divisors (see below), whose sum is σ = 16160160032. Its totient is φ = 8080080012.

The previous prime is 12120120011. The next prime is 12120120049. The reversal of 12120120021 is 12002102121.

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 not a de Polignac number, because 12120120021 - 2⁹ = 12120119509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12120119979 and 12120120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12120120011) 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, 2020020001 + ... + 2020020006.

It is an arithmetic number, because the mean of its divisors is an integer number (4040040008).

Almost surely, 2^12120120021 is an apocalyptic number.

It is an amenable number.

12120120021 is a deficient number, since it is larger than the sum of its proper divisors (4040040011).

12120120021 is an equidigital number, since it uses as much as digits as its factorization.

12120120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040040010.

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

Adding to 12120120021 its reverse (12002102121), we get a palindrome (24122222142).

The spelling of 12120120021 in words is "twelve billion, one hundred twenty million, one hundred twenty thousand, twenty-one".