28647971 has 8 divisors (see below), whose sum is σ = 32015088. Its totient is φ = 25408000.

The previous prime is 28647961. The next prime is 28647977. The reversal of 28647971 is 17974682.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28647971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28647977) 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 7 ways as a sum of consecutive naturals, for example, 31310 + ... + 32211.

It is an arithmetic number, because the mean of its divisors is an integer number (4001886).

Almost surely, 2^28647971 is an apocalyptic number.

28647971 is a deficient number, since it is larger than the sum of its proper divisors (3367117).

28647971 is a wasteful number, since it uses less digits than its factorization.

28647971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63573.

The product of its digits is 169344, while the sum is 44.

The square root of 28647971 is about 5352.3799379342. The cubic root of 28647971 is about 305.9834634434.

Subtracting from 28647971 its reverse (17974682), we obtain a square (10673289 = 3267²).

The spelling of 28647971 in words is "twenty-eight million, six hundred forty-seven thousand, nine hundred seventy-one".