15225421 has 4 divisors (see below), whose sum is σ = 16121052. Its totient is φ = 14329792.

The previous prime is 15225407. The next prime is 15225439. The reversal of 15225421 is 12452251.

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 6734025 + 8491396 = 2595^2 + 2914^2 .

It is a cyclic number.

It is not a de Polignac number, because 15225421 - 2⁷ = 15225293 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15225392 and 15225401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15225401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 447790 + ... + 447823.

It is an arithmetic number, because the mean of its divisors is an integer number (4030263).

Almost surely, 2^15225421 is an apocalyptic number.

It is an amenable number.

15225421 is a deficient number, since it is larger than the sum of its proper divisors (895631).

15225421 is an equidigital number, since it uses as much as digits as its factorization.

15225421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895630.

The product of its digits is 800, while the sum is 22.

The square root of 15225421 is about 3901.9765504165. The cubic root of 15225421 is about 247.8504832804.

Adding to 15225421 its reverse (12452251), we get a palindrome (27677672).

The spelling of 15225421 in words is "fifteen million, two hundred twenty-five thousand, four hundred twenty-one".