28642817 has 4 divisors (see below), whose sum is σ = 32734656. Its totient is φ = 24550980.

The previous prime is 28642811. The next prime is 28642819. The reversal of 28642817 is 71824682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71824682 = 2 ⋅35912341.

It is a cyclic number.

It is not a de Polignac number, because 28642817 - 2⁶ = 28642753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28642811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2045909 + ... + 2045922.

It is an arithmetic number, because the mean of its divisors is an integer number (8183664).

Almost surely, 2^28642817 is an apocalyptic number.

It is an amenable number.

28642817 is a deficient number, since it is larger than the sum of its proper divisors (4091839).

28642817 is an equidigital number, since it uses as much as digits as its factorization.

28642817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4091838.

The product of its digits is 43008, while the sum is 38.

The square root of 28642817 is about 5351.8984482144. The cubic root of 28642817 is about 305.9651127156.

The spelling of 28642817 in words is "twenty-eight million, six hundred forty-two thousand, eight hundred seventeen".