12212121021 has 16 divisors (see below), whose sum is σ = 16530596544. Its totient is φ = 8017599744.

The previous prime is 12212121013. The next prime is 12212121023. The reversal of 12212121021 is 12012121221.

It is not a de Polignac number, because 12212121021 - 2³ = 12212121013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12212121023) 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, 961911 + ... + 974523.

It is an arithmetic number, because the mean of its divisors is an integer number (1033162284).

Almost surely, 2^12212121021 is an apocalyptic number.

It is an amenable number.

12212121021 is a deficient number, since it is larger than the sum of its proper divisors (4318475523).

12212121021 is a wasteful number, since it uses less digits than its factorization.

12212121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17500.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 12212121021 its reverse (12012121221), we get a palindrome (24224242242).

The spelling of 12212121021 in words is "twelve billion, two hundred twelve million, one hundred twenty-one thousand, twenty-one".