28543643 has 4 divisors (see below), whose sum is σ = 30045960. Its totient is φ = 27041328.

The previous prime is 28543639. The next prime is 28543651. The reversal of 28543643 is 34634582.

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 28543643 - 2² = 28543639 is a prime.

It is a super-2 number, since 2×28543643² = 1629479111422898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28543673) 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, 751130 + ... + 751167.

It is an arithmetic number, because the mean of its divisors is an integer number (7511490).

Almost surely, 2^28543643 is an apocalyptic number.

28543643 is a deficient number, since it is larger than the sum of its proper divisors (1502317).

28543643 is a wasteful number, since it uses less digits than its factorization.

28543643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502316.

The product of its digits is 69120, while the sum is 35.

The square root of 28543643 is about 5342.6251038230. The cubic root of 28543643 is about 305.6115758786.

The spelling of 28543643 in words is "twenty-eight million, five hundred forty-three thousand, six hundred forty-three".