28043639 has 8 divisors (see below), whose sum is σ = 31790640. Its totient is φ = 24523776.

The previous prime is 28043627. The next prime is 28043641. The reversal of 28043639 is 93634082.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28043639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28043599 and 28043608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28043339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56522 + ... + 57015.

It is an arithmetic number, because the mean of its divisors is an integer number (3973830).

Almost surely, 2^28043639 is an apocalyptic number.

28043639 is a deficient number, since it is larger than the sum of its proper divisors (3747001).

28043639 is a wasteful number, since it uses less digits than its factorization.

28043639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113569.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 28043639 is about 5295.6245146347. The cubic root of 28043639 is about 303.8165697152.

It can be divided in two parts, 28043 and 639, that added together give a palindrome (28682).

The spelling of 28043639 in words is "twenty-eight million, forty-three thousand, six hundred thirty-nine".