122121212120221 has 4 divisors (see below), whose sum is σ = 123493360571100. Its totient is φ = 120749063669344.

The previous prime is 122121212120213. The next prime is 122121212120293. The reversal of 122121212120221 is 122021212121221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58762573205625 + 63358638914596 = 7665675^2 + 7959814^2 .

It is a cyclic number.

It is not a de Polignac number, because 122121212120221 - 2³ = 122121212120213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 122121212120192 and 122121212120201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (122121212120021) 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, 686074225306 + ... + 686074225483.

It is an arithmetic number, because the mean of its divisors is an integer number (30873340142775).

Almost surely, 2^{122121212120221} is an apocalyptic number.

It is an amenable number.

122121212120221 is a deficient number, since it is larger than the sum of its proper divisors (1372148450879).

122121212120221 is an equidigital number, since it uses as much as digits as its factorization.

122121212120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372148450878.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 122121212120221 its reverse (122021212121221), we get a palindrome (244142424241442).

The spelling of 122121212120221 in words is "one hundred twenty-two trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty thousand, two hundred twenty-one".