28539987 has 32 divisors (see below), whose sum is σ = 46636032. Its totient is φ = 15168384.

The previous prime is 28539967. The next prime is 28539989. The reversal of 28539987 is 78993582.

It is not a de Polignac number, because 28539987 - 2¹⁶ = 28474451 is a prime.

It is a super-3 number, since 3×28539987³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (28539989) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17073 + ... + 18669.

It is an arithmetic number, because the mean of its divisors is an integer number (1457376).

Almost surely, 2^28539987 is an apocalyptic number.

28539987 is a deficient number, since it is larger than the sum of its proper divisors (18096045).

28539987 is a wasteful number, since it uses less digits than its factorization.

28539987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1667.

The product of its digits is 1088640, while the sum is 51.

The square root of 28539987 is about 5342.2829389691. The cubic root of 28539987 is about 305.5985272799.

The spelling of 28539987 in words is "twenty-eight million, five hundred thirty-nine thousand, nine hundred eighty-seven".