28356647 has 4 divisors (see below), whose sum is σ = 30934536. Its totient is φ = 25778760.

The previous prime is 28356623. The next prime is 28356649. The reversal of 28356647 is 74665382.

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 28356647 - 2¹⁰ = 28355623 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 (28356649) 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 3 ways as a sum of consecutive naturals, for example, 1288928 + ... + 1288949.

It is an arithmetic number, because the mean of its divisors is an integer number (7733634).

Almost surely, 2^28356647 is an apocalyptic number.

28356647 is a deficient number, since it is larger than the sum of its proper divisors (2577889).

28356647 is a wasteful number, since it uses less digits than its factorization.

28356647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2577888.

The product of its digits is 241920, while the sum is 41.

The square root of 28356647 is about 5325.0959615767. The cubic root of 28356647 is about 304.9427358227.

The spelling of 28356647 in words is "twenty-eight million, three hundred fifty-six thousand, six hundred forty-seven".