28380307 has 4 divisors (see below), whose sum is σ = 28486080. Its totient is φ = 28274536.

The previous prime is 28380263. The next prime is 28380343. The reversal of 28380307 is 70308382.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28380307 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28380347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52483 + ... + 53020.

It is an arithmetic number, because the mean of its divisors is an integer number (7121520).

Almost surely, 2^28380307 is an apocalyptic number.

28380307 is a deficient number, since it is larger than the sum of its proper divisors (105773).

28380307 is a wasteful number, since it uses less digits than its factorization.

28380307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105772.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 28380307 is about 5327.3170545782. The cubic root of 28380307 is about 305.0275241666.

Adding to 28380307 its reverse (70308382), we get a palindrome (98688689).

The spelling of 28380307 in words is "twenty-eight million, three hundred eighty thousand, three hundred seven".