13220121021 has 4 divisors (see below), whose sum is σ = 17626828032. Its totient is φ = 8813414012.

The previous prime is 13220121011. The next prime is 13220121023. The reversal of 13220121021 is 12012102231.

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 13220121021 - 2⁶ = 13220120957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13220121023) 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, 2203353501 + ... + 2203353506.

It is an arithmetic number, because the mean of its divisors is an integer number (4406707008).

Almost surely, 2^13220121021 is an apocalyptic number.

It is an amenable number.

13220121021 is a deficient number, since it is larger than the sum of its proper divisors (4406707011).

13220121021 is an equidigital number, since it uses as much as digits as its factorization.

13220121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4406707010.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 13220121021 its reverse (12012102231), we get a palindrome (25232223252).

The spelling of 13220121021 in words is "thirteen billion, two hundred twenty million, one hundred twenty-one thousand, twenty-one".