13687120321 has 4 divisors (see below), whose sum is σ = 15642423232. Its totient is φ = 11731817412.

The previous prime is 13687120313. The next prime is 13687120351. The reversal of 13687120321 is 12302178631.

13687120321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 12302178631 = 6359 ⋅1934609.

It is not a de Polignac number, because 13687120321 - 2³ = 13687120313 is a prime.

It is a super-2 number, since 2×13687120321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13687120351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 977651445 + ... + 977651458.

It is an arithmetic number, because the mean of its divisors is an integer number (3910605808).

Almost surely, 2^13687120321 is an apocalyptic number.

It is an amenable number.

13687120321 is a deficient number, since it is larger than the sum of its proper divisors (1955302911).

13687120321 is an equidigital number, since it uses as much as digits as its factorization.

13687120321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1955302910.

The product of its (nonzero) digits is 12096, while the sum is 34.

Adding to 13687120321 its reverse (12302178631), we get a palindrome (25989298952).

The spelling of 13687120321 in words is "thirteen billion, six hundred eighty-seven million, one hundred twenty thousand, three hundred twenty-one".