28381525 has 6 divisors (see below), whose sum is σ = 35193122. Its totient is φ = 22705200.

The previous prime is 28381519. The next prime is 28381541. The reversal of 28381525 is 52518382.

It can be written as a sum of positive squares in 3 ways, for example, as 5885476 + 22496049 = 2426^2 + 4743^2 .

It is not a de Polignac number, because 28381525 - 2¹³ = 28373333 is a prime.

It is a super-2 number, since 2×28381525² = 1611021922651250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 567606 + ... + 567655.

Almost surely, 2^28381525 is an apocalyptic number.

28381525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28381525 is a deficient number, since it is larger than the sum of its proper divisors (6811597).

28381525 is a wasteful number, since it uses less digits than its factorization.

28381525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135271 (or 1135266 counting only the distinct ones).

The product of its digits is 19200, while the sum is 34.

The square root of 28381525 is about 5327.4313698067. The cubic root of 28381525 is about 305.0318877347.

The spelling of 28381525 in words is "twenty-eight million, three hundred eighty-one thousand, five hundred twenty-five".