28642725 has 18 divisors (see below), whose sum is σ = 51302706. Its totient is φ = 15276000.

The previous prime is 28642721. The next prime is 28642741. The reversal of 28642725 is 52724682.

28642725 is a `hidden beast` number, since 2 + 8 + 642 + 7 + 2 + 5 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 1425636 + 27217089 = 1194^2 + 5217^2 .

It is not a de Polignac number, because 28642725 - 2² = 28642721 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28642725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28642721) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 63426 + ... + 63875.

Almost surely, 2^28642725 is an apocalyptic number.

28642725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28642725 is a deficient number, since it is larger than the sum of its proper divisors (22659981).

28642725 is a wasteful number, since it uses less digits than its factorization.

28642725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127317 (or 127309 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The square root of 28642725 is about 5351.8898531267. The cubic root of 28642725 is about 305.9647851312.

The spelling of 28642725 in words is "twenty-eight million, six hundred forty-two thousand, seven hundred twenty-five".