121312321 has 16 divisors (see below), whose sum is σ = 139283200. Its totient is φ = 104727168.

The previous prime is 121312297. The next prime is 121312339. The reversal of 121312321 is 123213121.

It is not a de Polignac number, because 121312321 - 2¹⁵ = 121279553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121312295 and 121312304.

It is not an unprimeable number, because it can be changed into a prime (121312361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16405 + ... + 22621.

It is an arithmetic number, because the mean of its divisors is an integer number (8705200).

Almost surely, 2^121312321 is an apocalyptic number.

It is an amenable number.

121312321 is a deficient number, since it is larger than the sum of its proper divisors (17970879).

121312321 is a wasteful number, since it uses less digits than its factorization.

121312321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6328.

The product of its digits is 72, while the sum is 16.

The square root of 121312321 is about 11014.1872600751. The cubic root of 121312321 is about 495.0339343467.

Adding to 121312321 its reverse (123213121), we get a palindrome (244525442).

The spelling of 121312321 in words is "one hundred twenty-one million, three hundred twelve thousand, three hundred twenty-one".