28752639 has 4 divisors (see below), whose sum is σ = 38336856. Its totient is φ = 19168424.

The previous prime is 28752629. The next prime is 28752641. The reversal of 28752639 is 93625782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28752639 - 2⁹ = 28752127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28752639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28752629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4792104 + ... + 4792109.

It is an arithmetic number, because the mean of its divisors is an integer number (9584214).

Almost surely, 2^28752639 is an apocalyptic number.

28752639 is a deficient number, since it is larger than the sum of its proper divisors (9584217).

28752639 is an equidigital number, since it uses as much as digits as its factorization.

28752639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9584216.

The product of its digits is 181440, while the sum is 42.

The square root of 28752639 is about 5362.1487297538. The cubic root of 28752639 is about 306.3556567830.

The spelling of 28752639 in words is "twenty-eight million, seven hundred fifty-two thousand, six hundred thirty-nine".