121212202021 has 4 divisors (see below), whose sum is σ = 121245224544. Its totient is φ = 121179179500.

The previous prime is 121212201967. The next prime is 121212202037. The reversal of 121212202021 is 120202212121.

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 121212202021 - 2¹³ = 121212193829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121212201986 and 121212202004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212202051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16505755 + ... + 16513096.

It is an arithmetic number, because the mean of its divisors is an integer number (30311306136).

Almost surely, 2^121212202021 is an apocalyptic number.

It is an amenable number.

121212202021 is a deficient number, since it is larger than the sum of its proper divisors (33022523).

121212202021 is an equidigital number, since it uses as much as digits as its factorization.

121212202021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33022522.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 121212202021 its reverse (120202212121), we get a palindrome (241414414142).

The spelling of 121212202021 in words is "one hundred twenty-one billion, two hundred twelve million, two hundred two thousand, twenty-one".