122121212221 has 4 divisors (see below), whose sum is σ = 122338124352. Its totient is φ = 121904300092.

The previous prime is 122121212201. The next prime is 122121212249. The reversal of 122121212221 is 122212121221.

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: 122212121221 = 31 ⋅3942326491.

It is a cyclic number.

It is not a de Polignac number, because 122121212221 - 2¹¹ = 122121210173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (122121212201) 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, 108455221 + ... + 108456346.

It is an arithmetic number, because the mean of its divisors is an integer number (30584531088).

Almost surely, 2^122121212221 is an apocalyptic number.

It is an amenable number.

122121212221 is a deficient number, since it is larger than the sum of its proper divisors (216912131).

122121212221 is an equidigital number, since it uses as much as digits as its factorization.

122121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216912130.

The product of its digits is 128, while the sum is 19.

Adding to 122121212221 its reverse (122212121221), we get a palindrome (244333333442).

The spelling of 122121212221 in words is "one hundred twenty-two billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".