28333987 has 4 divisors (see below), whose sum is σ = 30909816. Its totient is φ = 25758160.

The previous prime is 28333967. The next prime is 28334003. The reversal of 28333987 is 78933382.

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 28333987 - 2¹¹ = 28331939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28333937) 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, 1287898 + ... + 1287919.

It is an arithmetic number, because the mean of its divisors is an integer number (7727454).

Almost surely, 2^28333987 is an apocalyptic number.

28333987 is a deficient number, since it is larger than the sum of its proper divisors (2575829).

28333987 is a wasteful number, since it uses less digits than its factorization.

28333987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2575828.

The product of its digits is 217728, while the sum is 43.

The square root of 28333987 is about 5322.9678751614. The cubic root of 28333987 is about 304.8614868676.

The spelling of 28333987 in words is "twenty-eight million, three hundred thirty-three thousand, nine hundred eighty-seven".