28739643 has 4 divisors (see below), whose sum is σ = 38319528. Its totient is φ = 19159760.

The previous prime is 28739617. The next prime is 28739681. The reversal of 28739643 is 34693782.

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 28739643 - 2⁵ = 28739611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28739595 and 28739604.

It is not an unprimeable number, because it can be changed into a prime (28739603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4789938 + ... + 4789943.

It is an arithmetic number, because the mean of its divisors is an integer number (9579882).

Almost surely, 2^28739643 is an apocalyptic number.

28739643 is a deficient number, since it is larger than the sum of its proper divisors (9579885).

28739643 is an equidigital number, since it uses as much as digits as its factorization.

28739643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9579884.

The product of its digits is 217728, while the sum is 42.

The square root of 28739643 is about 5360.9367651559. The cubic root of 28739643 is about 306.3094929262.

The spelling of 28739643 in words is "twenty-eight million, seven hundred thirty-nine thousand, six hundred forty-three".