28641663 has 12 divisors (see below), whose sum is σ = 42489928. Its totient is φ = 18578160.

The previous prime is 28641649. The next prime is 28641731. The reversal of 28641663 is 36614682.

28641663 is a `hidden beast` number, since 2 + 8 + 641 + 6 + 6 + 3 = 666.

It is not a de Polignac number, because 28641663 - 2⁸ = 28641407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28641563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42673 + ... + 43338.

Almost surely, 2^28641663 is an apocalyptic number.

28641663 is a deficient number, since it is larger than the sum of its proper divisors (13848265).

28641663 is a wasteful number, since it uses less digits than its factorization.

28641663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86054 (or 86051 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 28641663 is about 5351.7906349184. The cubic root of 28641663 is about 305.9610036170.

The spelling of 28641663 in words is "twenty-eight million, six hundred forty-one thousand, six hundred sixty-three".