121020021221 has 4 divisors (see below), whose sum is σ = 132021841344. Its totient is φ = 110018201100.

The previous prime is 121020021193. The next prime is 121020021247. The reversal of 121020021221 is 122120020121.

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: 122120020121 = 11 ⋅11101820011.

It is a cyclic number.

It is not a de Polignac number, because 121020021221 - 2²⁶ = 120952912357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121020021196 and 121020021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121020021251) 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, 5500910045 + ... + 5500910066.

It is an arithmetic number, because the mean of its divisors is an integer number (33005460336).

Almost surely, 2^121020021221 is an apocalyptic number.

121020021221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121020021221 is a deficient number, since it is larger than the sum of its proper divisors (11001820123).

121020021221 is a wasteful number, since it uses less digits than its factorization.

121020021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11001820122.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 121020021221 its reverse (122120020121), we get a palindrome (243140041342).

The spelling of 121020021221 in words is "one hundred twenty-one billion, twenty million, twenty-one thousand, two hundred twenty-one".