28645 has 8 divisors (see below), whose sum is σ = 36504. Its totient is φ = 21504.

The previous prime is 28643. The next prime is 28649. The reversal of 28645 is 54682.

It can be written as a sum of positive squares in 4 ways, for example, as 3364 + 25281 = 58^2 + 159^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 5-Lehmer number, since φ(28645) divides (28645-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 28645 - 2¹ = 28643 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28643) 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 7 ways as a sum of consecutive naturals, for example, 84 + ... + 253.

It is an arithmetic number, because the mean of its divisors is an integer number (4563).

2²⁸⁶⁴⁵ is an apocalyptic number.

28645 is the 85-th decagonal number.

It is an amenable number.

28645 is a deficient number, since it is larger than the sum of its proper divisors (7859).

28645 is a wasteful number, since it uses less digits than its factorization.

28645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359.

The product of its digits is 1920, while the sum is 25.

The square root of 28645 is about 169.2483382489. The cubic root of 28645 is about 30.5972885518.

The spelling of 28645 in words is "twenty-eight thousand, six hundred forty-five".