28843991 has 8 divisors (see below), whose sum is σ = 31661184. Its totient is φ = 26059320.

The previous prime is 28843949. The next prime is 28843993. The reversal of 28843991 is 19934882.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28843991 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 (28843993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6251 + ... + 9836.

It is an arithmetic number, because the mean of its divisors is an integer number (3957648).

Almost surely, 2^28843991 is an apocalyptic number.

28843991 is a deficient number, since it is larger than the sum of its proper divisors (2817193).

28843991 is a wasteful number, since it uses less digits than its factorization.

28843991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16261.

The product of its digits is 124416, while the sum is 44.

The square root of 28843991 is about 5370.6602015022. The cubic root of 28843991 is about 306.6797617019.

The spelling of 28843991 in words is "twenty-eight million, eight hundred forty-three thousand, nine hundred ninety-one".