15242321 has 4 divisors (see below), whose sum is σ = 15276132. Its totient is φ = 15208512.

The previous prime is 15242317. The next prime is 15242329. The reversal of 15242321 is 12324251.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7182400 + 8059921 = 2680^2 + 2839^2 .

It is a cyclic number.

It is not a de Polignac number, because 15242321 - 2² = 15242317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15242293 and 15242302.

It is not an unprimeable number, because it can be changed into a prime (15242329) 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, 16220 + ... + 17133.

It is an arithmetic number, because the mean of its divisors is an integer number (3819033).

Almost surely, 2^15242321 is an apocalyptic number.

It is an amenable number.

15242321 is a deficient number, since it is larger than the sum of its proper divisors (33811).

15242321 is an equidigital number, since it uses as much as digits as its factorization.

15242321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33810.

The product of its digits is 480, while the sum is 20.

The square root of 15242321 is about 3904.1415189514. The cubic root of 15242321 is about 247.9421528711.

Adding to 15242321 its reverse (12324251), we get a palindrome (27566572).

The spelling of 15242321 in words is "fifteen million, two hundred forty-two thousand, three hundred twenty-one".