28259991 has 12 divisors (see below), whose sum is σ = 40867632. Its totient is φ = 18818016.

The previous prime is 28259969. The next prime is 28260017. The reversal of 28259991 is 19995282.

It is not a de Polignac number, because 28259991 - 2¹³ = 28251799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28259921) 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, 11155 + ... + 13451.

It is an arithmetic number, because the mean of its divisors is an integer number (3405636).

Almost surely, 2^28259991 is an apocalyptic number.

28259991 is a deficient number, since it is larger than the sum of its proper divisors (12607641).

28259991 is a wasteful number, since it uses less digits than its factorization.

28259991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3670 (or 3667 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 28259991 is about 5316.0126975018. The cubic root of 28259991 is about 304.5958671509.

The spelling of 28259991 in words is "twenty-eight million, two hundred fifty-nine thousand, nine hundred ninety-one".