28748639 has 8 divisors (see below), whose sum is σ = 29707392. Its totient is φ = 27803160.

The previous prime is 28748633. The next prime is 28748647. The reversal of 28748639 is 93684782.

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 28748639 - 2⁸ = 28748383 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28748593 and 28748602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28748633) 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, 1184 + ... + 7674.

It is an arithmetic number, because the mean of its divisors is an integer number (3713424).

Almost surely, 2^28748639 is an apocalyptic number.

28748639 is a deficient number, since it is larger than the sum of its proper divisors (958753).

28748639 is a wasteful number, since it uses less digits than its factorization.

28748639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6637.

The product of its digits is 580608, while the sum is 47.

The square root of 28748639 is about 5361.7757319754. The cubic root of 28748639 is about 306.3414496296.

The spelling of 28748639 in words is "twenty-eight million, seven hundred forty-eight thousand, six hundred thirty-nine".