28691839 has 4 divisors (see below), whose sum is σ = 31300200. Its totient is φ = 26083480.

The previous prime is 28691837. The next prime is 28691867. The reversal of 28691839 is 93819682.

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 28691839 - 2¹ = 28691837 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 (28691837) 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, 1304164 + ... + 1304185.

It is an arithmetic number, because the mean of its divisors is an integer number (7825050).

Almost surely, 2^28691839 is an apocalyptic number.

28691839 is a deficient number, since it is larger than the sum of its proper divisors (2608361).

28691839 is a wasteful number, since it uses less digits than its factorization.

28691839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2608360.

The product of its digits is 186624, while the sum is 46.

The square root of 28691839 is about 5356.4763604444. The cubic root of 28691839 is about 306.1395656797.

The spelling of 28691839 in words is "twenty-eight million, six hundred ninety-one thousand, eight hundred thirty-nine".