28658638 has 4 divisors (see below), whose sum is σ = 42987960. Its totient is φ = 14329318.

The previous prime is 28658633. The next prime is 28658639. The reversal of 28658638 is 83685682.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28658633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7164658 + ... + 7164661.

It is an arithmetic number, because the mean of its divisors is an integer number (10746990).

Almost surely, 2^28658638 is an apocalyptic number.

28658638 is the 2862-nd centered heptagonal number.

28658638 is a deficient number, since it is larger than the sum of its proper divisors (14329322).

28658638 is a wasteful number, since it uses less digits than its factorization.

28658638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14329321.

The product of its digits is 552960, while the sum is 46.

The square root of 28658638 is about 5353.3763178017. The cubic root of 28658638 is about 306.0214361220.

The spelling of 28658638 in words is "twenty-eight million, six hundred fifty-eight thousand, six hundred thirty-eight".