12121012021 has 4 divisors (see below), whose sum is σ = 12124086912. Its totient is φ = 12117937132.

The previous prime is 12121011989. The next prime is 12121012037. The reversal of 12121012021 is 12021012121.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12021012121 = 74047 ⋅162343.

It is a cyclic number.

It is not a de Polignac number, because 12121012021 - 2⁵ = 12121011989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121011992 and 12121012010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121012061) 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, 1531525 + ... + 1539418.

It is an arithmetic number, because the mean of its divisors is an integer number (3031021728).

Almost surely, 2^12121012021 is an apocalyptic number.

It is an amenable number.

12121012021 is a deficient number, since it is larger than the sum of its proper divisors (3074891).

12121012021 is an equidigital number, since it uses as much as digits as its factorization.

12121012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3074890.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 12121012021 its reverse (12021012121), we get a palindrome (24142024142).

The spelling of 12121012021 in words is "twelve billion, one hundred twenty-one million, twelve thousand, twenty-one".