12221525 has 6 divisors (see below), whose sum is σ = 15154722. Its totient is φ = 9777200.

The previous prime is 12221519. The next prime is 12221527. The reversal of 12221525 is 52512221.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3034564 + 9186961 = 1742^2 + 3031^2 .

It is not a de Polignac number, because 12221525 - 2¹⁶ = 12155989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12221497 and 12221506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221527) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 244406 + ... + 244455.

It is an arithmetic number, because the mean of its divisors is an integer number (2525787).

Almost surely, 2^12221525 is an apocalyptic number.

It is an amenable number.

12221525 is a deficient number, since it is larger than the sum of its proper divisors (2933197).

12221525 is an equidigital number, since it uses as much as digits as its factorization.

12221525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488871 (or 488866 counting only the distinct ones).

The product of its digits is 400, while the sum is 20.

The square root of 12221525 is about 3495.9297761826. The cubic root of 12221525 is about 230.3430608256.

Adding to 12221525 its reverse (52512221), we get a palindrome (64733746).

The spelling of 12221525 in words is "twelve million, two hundred twenty-one thousand, five hundred twenty-five".