28644705 has 16 divisors (see below), whose sum is σ = 50924160. Its totient is φ = 15277104.

The previous prime is 28644701. The next prime is 28644719. The reversal of 28644705 is 50744682.

28644705 is a `hidden beast` number, since 2 + 8 + 644 + 7 + 0 + 5 = 666.

It is not a de Polignac number, because 28644705 - 2² = 28644701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28644705.

It is not an unprimeable number, because it can be changed into a prime (28644701) 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, 105957 + ... + 106226.

It is an arithmetic number, because the mean of its divisors is an integer number (3182760).

Almost surely, 2^28644705 is an apocalyptic number.

It is an amenable number.

28644705 is a deficient number, since it is larger than the sum of its proper divisors (22279455).

28644705 is a wasteful number, since it uses less digits than its factorization.

28644705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212197 (or 212191 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 28644705 is about 5352.0748313154. The cubic root of 28644705 is about 305.9718351624.

It can be divided in two parts, 2864 and 4705, that added together give a square (7569 = 87²).

The spelling of 28644705 in words is "twenty-eight million, six hundred forty-four thousand, seven hundred five".