13820205121 has 4 divisors (see below), whose sum is σ = 13821287472. Its totient is φ = 13819122772.

The previous prime is 13820205041. The next prime is 13820205137. The reversal of 13820205121 is 12150202831.

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 a de Polignac number, because none of the positive numbers 2^k-13820205121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13820205181) 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, 521791 + ... + 547636.

It is an arithmetic number, because the mean of its divisors is an integer number (3455321868).

Almost surely, 2^13820205121 is an apocalyptic number.

It is an amenable number.

13820205121 is a deficient number, since it is larger than the sum of its proper divisors (1082351).

13820205121 is a wasteful number, since it uses less digits than its factorization.

13820205121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082350.

The product of its (nonzero) digits is 960, while the sum is 25.

Adding to 13820205121 its reverse (12150202831), we get a palindrome (25970407952).

The spelling of 13820205121 in words is "thirteen billion, eight hundred twenty million, two hundred five thousand, one hundred twenty-one".