28747439 has 8 divisors (see below), whose sum is σ = 33987360. Its totient is φ = 23790816.

The previous prime is 28747429. The next prime is 28747471. The reversal of 28747439 is 93474782.

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

It is a de Polignac number, because none of the positive numbers 2^k-28747439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28747439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28747429) 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, 70604 + ... + 71009.

It is an arithmetic number, because the mean of its divisors is an integer number (4248420).

Almost surely, 2^28747439 is an apocalyptic number.

28747439 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28747439 is a deficient number, since it is larger than the sum of its proper divisors (5239921).

28747439 is a wasteful number, since it uses less digits than its factorization.

28747439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141649.

The product of its digits is 338688, while the sum is 44.

The square root of 28747439 is about 5361.6638275819. The cubic root of 28747439 is about 306.3371872266.

Adding to 28747439 its reverse (93474782), we get a palindrome (122222221).

The spelling of 28747439 in words is "twenty-eight million, seven hundred forty-seven thousand, four hundred thirty-nine".