15221249 has 4 divisors (see below), whose sum is σ = 15256836. Its totient is φ = 15185664.

The previous prime is 15221243. The next prime is 15221251. The reversal of 15221249 is 94212251.

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 628849 + 14592400 = 793^2 + 3820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15221249 is a prime.

It is a super-2 number, since 2×15221249² = 463372842240002, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15221243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17144 + ... + 18009.

It is an arithmetic number, because the mean of its divisors is an integer number (3814209).

Almost surely, 2^15221249 is an apocalyptic number.

It is an amenable number.

15221249 is a deficient number, since it is larger than the sum of its proper divisors (35587).

15221249 is an equidigital number, since it uses as much as digits as its factorization.

15221249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35586.

The product of its digits is 1440, while the sum is 26.

The square root of 15221249 is about 3901.4419129342. The cubic root of 15221249 is about 247.8278429283.

The spelling of 15221249 in words is "fifteen million, two hundred twenty-one thousand, two hundred forty-nine".