28638671 has 4 divisors (see below), whose sum is σ = 28656144. Its totient is φ = 28621200.

The previous prime is 28638647. The next prime is 28638679. The reversal of 28638671 is 17683682.

It is a happy number.

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 28638671 - 2¹⁴ = 28622287 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 (28638679) 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, 5990 + ... + 9651.

It is an arithmetic number, because the mean of its divisors is an integer number (7164036).

Almost surely, 2^28638671 is an apocalyptic number.

28638671 is a deficient number, since it is larger than the sum of its proper divisors (17473).

28638671 is a wasteful number, since it uses less digits than its factorization.

28638671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17472.

The product of its digits is 96768, while the sum is 41.

The square root of 28638671 is about 5351.5110950086. The cubic root of 28638671 is about 305.9503493567.

The spelling of 28638671 in words is "twenty-eight million, six hundred thirty-eight thousand, six hundred seventy-one".