28728887 has 8 divisors (see below), whose sum is σ = 31473552. Its totient is φ = 26006400.

The previous prime is 28728881. The next prime is 28728911. The reversal of 28728887 is 78882782.

It is a happy number.

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 28728887 - 2⁸ = 28728631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2768 + ... + 8069.

It is an arithmetic number, because the mean of its divisors is an integer number (3934194).

Almost surely, 2^28728887 is an apocalyptic number.

28728887 is a deficient number, since it is larger than the sum of its proper divisors (2744665).

28728887 is a wasteful number, since it uses less digits than its factorization.

28728887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11089.

The product of its digits is 802816, while the sum is 50.

The square root of 28728887 is about 5359.9334883933. The cubic root of 28728887 is about 306.2712753788.

The spelling of 28728887 in words is "twenty-eight million, seven hundred twenty-eight thousand, eight hundred eighty-seven".