28873691 has 12 divisors (see below), whose sum is σ = 36641880. Its totient is φ = 22498560.

The previous prime is 28873687. The next prime is 28873721. The reversal of 28873691 is 19637882.

It is not a de Polignac number, because 28873691 - 2² = 28873687 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28873601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26246 + ... + 27323.

It is an arithmetic number, because the mean of its divisors is an integer number (3053490).

Almost surely, 2^28873691 is an apocalyptic number.

28873691 is a deficient number, since it is larger than the sum of its proper divisors (7768189).

28873691 is a wasteful number, since it uses less digits than its factorization.

28873691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53594 (or 53587 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 28873691 is about 5373.4245132876. The cubic root of 28873691 is about 306.7849859810.

The spelling of 28873691 in words is "twenty-eight million, eight hundred seventy-three thousand, six hundred ninety-one".