28581887 has 4 divisors (see below), whose sum is σ = 28757400. Its totient is φ = 28406376.

The previous prime is 28581829. The next prime is 28581911. The reversal of 28581887 is 78818582.

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 28581887 - 2⁶ = 28581823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28581587) 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, 87512 + ... + 87837.

It is an arithmetic number, because the mean of its divisors is an integer number (7189350).

Almost surely, 2^28581887 is an apocalyptic number.

28581887 is a deficient number, since it is larger than the sum of its proper divisors (175513).

28581887 is a wasteful number, since it uses less digits than its factorization.

28581887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175512.

The product of its digits is 286720, while the sum is 47.

The square root of 28581887 is about 5346.2030451527. The cubic root of 28581887 is about 305.7480054746.

The spelling of 28581887 in words is "twenty-eight million, five hundred eighty-one thousand, eight hundred eighty-seven".