28208525 has 12 divisors (see below), whose sum is σ = 37036692. Its totient is φ = 21239040.

The previous prime is 28208489. The next prime is 28208539. The reversal of 28208525 is 52580282.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2937796 + 25270729 = 1714^2 + 5027^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28208525 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28208491 and 28208500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32762 + ... + 33611.

It is an arithmetic number, because the mean of its divisors is an integer number (3086391).

Almost surely, 2^28208525 is an apocalyptic number.

28208525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28208525 is a deficient number, since it is larger than the sum of its proper divisors (8828167).

28208525 is a wasteful number, since it uses less digits than its factorization.

28208525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66400 (or 66395 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 32.

The square root of 28208525 is about 5311.1698334736. The cubic root of 28208525 is about 304.4108487278.

The spelling of 28208525 in words is "twenty-eight million, two hundred eight thousand, five hundred twenty-five".