15115421 has 4 divisors (see below), whose sum is σ = 15139644. Its totient is φ = 15091200.

The previous prime is 15115417. The next prime is 15115427. The reversal of 15115421 is 12451151.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12451151 = 283 ⋅43997.

It can be written as a sum of positive squares in 2 ways, for example, as 9302500 + 5812921 = 3050^2 + 2411^2 .

It is a cyclic number.

It is not a de Polignac number, because 15115421 - 2² = 15115417 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15115393 and 15115402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15115427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11150 + ... + 12431.

It is an arithmetic number, because the mean of its divisors is an integer number (3784911).

Almost surely, 2^15115421 is an apocalyptic number.

It is an amenable number.

15115421 is a deficient number, since it is larger than the sum of its proper divisors (24223).

15115421 is an equidigital number, since it uses as much as digits as its factorization.

15115421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24222.

The product of its digits is 200, while the sum is 20.

The square root of 15115421 is about 3887.8555785934. The cubic root of 15115421 is about 247.2521533447.

Adding to 15115421 its reverse (12451151), we get a palindrome (27566572).

The spelling of 15115421 in words is "fifteen million, one hundred fifteen thousand, four hundred twenty-one".