28159643 has 4 divisors (see below), whose sum is σ = 28197600. Its totient is φ = 28121688.

The previous prime is 28159639. The next prime is 28159657. The reversal of 28159643 is 34695182.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34695182 = 2 ⋅17347591.

It is a cyclic number.

It is not a de Polignac number, because 28159643 - 2² = 28159639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28159597 and 28159606.

It is not an unprimeable number, because it can be changed into a prime (28159603) 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, 17843 + ... + 19356.

It is an arithmetic number, because the mean of its divisors is an integer number (7049400).

Almost surely, 2^28159643 is an apocalyptic number.

28159643 is a deficient number, since it is larger than the sum of its proper divisors (37957).

28159643 is an equidigital number, since it uses as much as digits as its factorization.

28159643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37956.

The product of its digits is 51840, while the sum is 38.

The square root of 28159643 is about 5306.5660271026. The cubic root of 28159643 is about 304.2349111983.

The spelling of 28159643 in words is "twenty-eight million, one hundred fifty-nine thousand, six hundred forty-three".