28240539 has 4 divisors (see below), whose sum is σ = 37654056. Its totient is φ = 18827024.

The previous prime is 28240529. The next prime is 28240543. The reversal of 28240539 is 93504282.

It is a happy number.

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 28240539 - 2⁹ = 28240027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28240529) 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, 4706754 + ... + 4706759.

It is an arithmetic number, because the mean of its divisors is an integer number (9413514).

Almost surely, 2^28240539 is an apocalyptic number.

28240539 is a deficient number, since it is larger than the sum of its proper divisors (9413517).

28240539 is an equidigital number, since it uses as much as digits as its factorization.

28240539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9413516.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 28240539 is about 5314.1828158241. The cubic root of 28240539 is about 304.5259643359.

The spelling of 28240539 in words is "twenty-eight million, two hundred forty thousand, five hundred thirty-nine".