28644505 has 8 divisors (see below), whose sum is σ = 34605000. Its totient is φ = 22761216.

The previous prime is 28644491. The next prime is 28644523. The reversal of 28644505 is 50544682.

It can be written as a sum of positive squares in 4 ways, for example, as 1646089 + 26998416 = 1283^2 + 5196^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 28644505 - 2⁷ = 28644377 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18480 + ... + 19969.

It is an arithmetic number, because the mean of its divisors is an integer number (4325625).

Almost surely, 2^28644505 is an apocalyptic number.

It is an amenable number.

28644505 is a deficient number, since it is larger than the sum of its proper divisors (5960495).

28644505 is a wasteful number, since it uses less digits than its factorization.

28644505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38603.

The product of its (nonzero) digits is 38400, while the sum is 34.

The square root of 28644505 is about 5352.0561469402. The cubic root of 28644505 is about 305.9711230528.

The spelling of 28644505 in words is "twenty-eight million, six hundred forty-four thousand, five hundred five".