27728971 has 4 divisors (see below), whose sum is σ = 27928600. Its totient is φ = 27529344.

The previous prime is 27728963. The next prime is 27728993. The reversal of 27728971 is 17982772.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 27728971 - 2³ = 27728963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27728951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99606 + ... + 99883.

It is an arithmetic number, because the mean of its divisors is an integer number (6982150).

Almost surely, 2^27728971 is an apocalyptic number.

27728971 is a deficient number, since it is larger than the sum of its proper divisors (199629).

27728971 is a wasteful number, since it uses less digits than its factorization.

27728971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199628.

The product of its digits is 98784, while the sum is 43.

The square root of 27728971 is about 5265.8305137936. The cubic root of 27728971 is about 302.6759525496.

The spelling of 27728971 in words is "twenty-seven million, seven hundred twenty-eight thousand, nine hundred seventy-one".