15225215 has 4 divisors (see below), whose sum is σ = 18270264. Its totient is φ = 12180168.

The previous prime is 15225181. The next prime is 15225233. The reversal of 15225215 is 51252251.

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

It is a cyclic number.

It is not a de Polignac number, because 15225215 - 2¹⁸ = 14963071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1522517 + ... + 1522526.

It is an arithmetic number, because the mean of its divisors is an integer number (4567566).

Almost surely, 2^15225215 is an apocalyptic number.

15225215 is a deficient number, since it is larger than the sum of its proper divisors (3045049).

15225215 is an equidigital number, since it uses as much as digits as its factorization.

15225215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3045048.

The product of its digits is 1000, while the sum is 23.

The square root of 15225215 is about 3901.9501534489. The cubic root of 15225215 is about 247.8493654694.

Adding to 15225215 its reverse (51252251), we get a palindrome (66477466).

The spelling of 15225215 in words is "fifteen million, two hundred twenty-five thousand, two hundred fifteen".