28133439 has 16 divisors (see below), whose sum is σ = 39308544. Its totient is φ = 17864000.

The previous prime is 28133437. The next prime is 28133459. The reversal of 28133439 is 93433182.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28133439 - 2¹ = 28133437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28133437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18664 + ... + 20114.

It is an arithmetic number, because the mean of its divisors is an integer number (2456784).

Almost surely, 2^28133439 is an apocalyptic number.

28133439 is a deficient number, since it is larger than the sum of its proper divisors (11175105).

28133439 is a wasteful number, since it uses less digits than its factorization.

28133439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758.

The product of its digits is 15552, while the sum is 33.

The square root of 28133439 is about 5304.0964357749. The cubic root of 28133439 is about 304.1405131534.

The spelling of 28133439 in words is "twenty-eight million, one hundred thirty-three thousand, four hundred thirty-nine".