28208739 has 16 divisors (see below), whose sum is σ = 40600224. Its totient is φ = 17318400.

The previous prime is 28208723. The next prime is 28208759. The reversal of 28208739 is 93780282.

It is not a de Polignac number, because 28208739 - 2⁴ = 28208723 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 28208697 and 28208706.

It is not an unprimeable number, because it can be changed into a prime (28208759) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31579 + ... + 32459.

It is an arithmetic number, because the mean of its divisors is an integer number (2537514).

Almost surely, 2^28208739 is an apocalyptic number.

28208739 is a deficient number, since it is larger than the sum of its proper divisors (12391485).

28208739 is a wasteful number, since it uses less digits than its factorization.

28208739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 28208739 is about 5311.1899796562. The cubic root of 28208739 is about 304.4116185158.

The spelling of 28208739 in words is "twenty-eight million, two hundred eight thousand, seven hundred thirty-nine".