28325639 has 4 divisors (see below), whose sum is σ = 28336560. Its totient is φ = 28314720.

The previous prime is 28325623. The next prime is 28325641. The reversal of 28325639 is 93652382.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 93652382 = 2 ⋅46826191.

It is a cyclic number.

It is not a de Polignac number, because 28325639 - 2⁴ = 28325623 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 (28325669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 902 + ... + 7580.

It is an arithmetic number, because the mean of its divisors is an integer number (7084140).

Almost surely, 2^28325639 is an apocalyptic number.

28325639 is a deficient number, since it is larger than the sum of its proper divisors (10921).

28325639 is an equidigital number, since it uses as much as digits as its factorization.

28325639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10920.

The product of its digits is 77760, while the sum is 38.

The square root of 28325639 is about 5322.1836683827. The cubic root of 28325639 is about 304.8315436328.

The spelling of 28325639 in words is "twenty-eight million, three hundred twenty-five thousand, six hundred thirty-nine".