28236643 has 8 divisors (see below), whose sum is σ = 29944512. Its totient is φ = 26534016.

The previous prime is 28236631. The next prime is 28236647. The reversal of 28236643 is 34663282.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28236643 - 2¹³ = 28228451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28236599 and 28236608.

It is not an unprimeable number, because it can be changed into a prime (28236647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18246 + ... + 19732.

It is an arithmetic number, because the mean of its divisors is an integer number (3743064).

Almost surely, 2^28236643 is an apocalyptic number.

28236643 is a deficient number, since it is larger than the sum of its proper divisors (1707869).

28236643 is a wasteful number, since it uses less digits than its factorization.

28236643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2621.

The product of its digits is 41472, while the sum is 34.

The square root of 28236643 is about 5313.8162369431. The cubic root of 28236643 is about 304.5119597906.

The spelling of 28236643 in words is "twenty-eight million, two hundred thirty-six thousand, six hundred forty-three".