28644905 has 8 divisors (see below), whose sum is σ = 34403784. Its totient is φ = 22896000.

The previous prime is 28644901. The next prime is 28644911. The reversal of 28644905 is 50944682.

It can be written as a sum of positive squares in 4 ways, for example, as 565504 + 28079401 = 752^2 + 5299^2 .

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

It is not a de Polignac number, because 28644905 - 2² = 28644901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28644901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7415 + ... + 10595.

It is an arithmetic number, because the mean of its divisors is an integer number (4300473).

Almost surely, 2^28644905 is an apocalyptic number.

It is an amenable number.

28644905 is a deficient number, since it is larger than the sum of its proper divisors (5758879).

28644905 is a wasteful number, since it uses less digits than its factorization.

28644905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4987.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 28644905 is about 5352.0935156255. The cubic root of 28644905 is about 305.9725472687.

The spelling of 28644905 in words is "twenty-eight million, six hundred forty-four thousand, nine hundred five".