28133525 has 24 divisors (see below), whose sum is σ = 40068864. Its totient is φ = 19195200.

The previous prime is 28133507. The next prime is 28133527. The reversal of 28133525 is 52533182.

It is a de Polignac number, because none of the positive numbers 2^k-28133525 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28133527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65060 + ... + 65490.

It is an arithmetic number, because the mean of its divisors is an integer number (1669536).

Almost surely, 2^28133525 is an apocalyptic number.

28133525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28133525 is a deficient number, since it is larger than the sum of its proper divisors (11935339).

28133525 is a wasteful number, since it uses less digits than its factorization.

28133525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821 (or 816 counting only the distinct ones).

The product of its digits is 7200, while the sum is 29.

The square root of 28133525 is about 5304.1045427103. The cubic root of 28133525 is about 304.1408230581.

The spelling of 28133525 in words is "twenty-eight million, one hundred thirty-three thousand, five hundred twenty-five".