28638587 has 4 divisors (see below), whose sum is σ = 28844760. Its totient is φ = 28432416.

The previous prime is 28638583. The next prime is 28638613. The reversal of 28638587 is 78583682.

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 28638587 - 2² = 28638583 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28638581) 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, 102878 + ... + 103155.

It is an arithmetic number, because the mean of its divisors is an integer number (7211190).

Almost surely, 2^28638587 is an apocalyptic number.

28638587 is a deficient number, since it is larger than the sum of its proper divisors (206173).

28638587 is a wasteful number, since it uses less digits than its factorization.

28638587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206172.

The product of its digits is 645120, while the sum is 47.

The square root of 28638587 is about 5351.5032467523. The cubic root of 28638587 is about 305.9500502290.

The spelling of 28638587 in words is "twenty-eight million, six hundred thirty-eight thousand, five hundred eighty-seven".