28337891 has 4 divisors (see below), whose sum is σ = 28561152. Its totient is φ = 28114632.

The previous prime is 28337887. The next prime is 28337899. The reversal of 28337891 is 19873382.

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 28337891 - 2² = 28337887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28337899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111440 + ... + 111693.

It is an arithmetic number, because the mean of its divisors is an integer number (7140288).

Almost surely, 2^28337891 is an apocalyptic number.

28337891 is a deficient number, since it is larger than the sum of its proper divisors (223261).

28337891 is a wasteful number, since it uses less digits than its factorization.

28337891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223260.

The product of its digits is 72576, while the sum is 41.

The square root of 28337891 is about 5323.3345752451. The cubic root of 28337891 is about 304.8754880103.

The spelling of 28337891 in words is "twenty-eight million, three hundred thirty-seven thousand, eight hundred ninety-one".