28640547 has 40 divisors (see below), whose sum is σ = 46957680. Its totient is φ = 17288640.

The previous prime is 28640527. The next prime is 28640551. The reversal of 28640547 is 74504682.

28640547 is a `hidden beast` number, since 2 + 8 + 640 + 5 + 4 + 7 = 666.

It is not a de Polignac number, because 28640547 - 2⁶ = 28640483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28640527) 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 39 ways as a sum of consecutive naturals, for example, 61897 + ... + 62357.

It is an arithmetic number, because the mean of its divisors is an integer number (1173942).

Almost surely, 2^28640547 is an apocalyptic number.

28640547 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28640547 is a deficient number, since it is larger than the sum of its proper divisors (18317133).

28640547 is a wasteful number, since it uses less digits than its factorization.

28640547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545 (or 536 counting only the distinct ones).

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

The square root of 28640547 is about 5351.6863697343. The cubic root of 28640547 is about 305.9570297216.

The spelling of 28640547 in words is "twenty-eight million, six hundred forty thousand, five hundred forty-seven".