15121321 has 8 divisors (see below), whose sum is σ = 16060320. Its totient is φ = 14196672.

The previous prime is 15121307. The next prime is 15121331. The reversal of 15121321 is 12312151.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15121321 - 2¹⁵ = 15088553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 15121295 and 15121304.

It is not an unprimeable number, because it can be changed into a prime (15121331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1375 + ... + 5668.

It is an arithmetic number, because the mean of its divisors is an integer number (2007540).

Almost surely, 2^15121321 is an apocalyptic number.

It is an amenable number.

15121321 is a deficient number, since it is larger than the sum of its proper divisors (938999).

15121321 is a wasteful number, since it uses less digits than its factorization.

15121321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7175.

The product of its digits is 60, while the sum is 16.

The square root of 15121321 is about 3888.6142776058. The cubic root of 15121321 is about 247.2843191252.

Adding to 15121321 its reverse (12312151), we get a palindrome (27433472).

The spelling of 15121321 in words is "fifteen million, one hundred twenty-one thousand, three hundred twenty-one".