12505428 has 60 divisors (see below), whose sum is σ = 35218260. Its totient is φ = 3846528.

The previous prime is 12505417. The next prime is 12505457. The reversal of 12505428 is 82450521.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 685584 + 11819844 = 828^2 + 3438^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 2728 + ... + 5696.

It is an arithmetic number, because the mean of its divisors is an integer number (586971).

Almost surely, 2^12505428 is an apocalyptic number.

12505428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12505428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17609130).

12505428 is an abundant number, since it is smaller than the sum of its proper divisors (22712832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12505428 is a wasteful number, since it uses less digits than its factorization.

12505428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2998 (or 2987 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 12505428 is about 3536.3014577380. The cubic root of 12505428 is about 232.1130295450.

Adding to 12505428 its reverse (82450521), we get a palindrome (94955949).

The spelling of 12505428 in words is "twelve million, five hundred five thousand, four hundred twenty-eight".