28938487 has 4 divisors (see below), whose sum is σ = 29068480. Its totient is φ = 28808496.

The previous prime is 28938451. The next prime is 28938517. The reversal of 28938487 is 78483982.

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 28938487 - 2¹⁵ = 28905719 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 28938487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28938787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64662 + ... + 65107.

It is an arithmetic number, because the mean of its divisors is an integer number (7267120).

Almost surely, 2^28938487 is an apocalyptic number.

28938487 is a deficient number, since it is larger than the sum of its proper divisors (129993).

28938487 is a wasteful number, since it uses less digits than its factorization.

28938487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129992.

The product of its digits is 774144, while the sum is 49.

The square root of 28938487 is about 5379.4504366152. The cubic root of 28938487 is about 307.0143018727.

The spelling of 28938487 in words is "twenty-eight million, nine hundred thirty-eight thousand, four hundred eighty-seven".