28248991 has 16 divisors (see below), whose sum is σ = 31334400. Its totient is φ = 25347168.

The previous prime is 28248977. The next prime is 28249027. The reversal of 28248991 is 19984282.

It is not a de Polignac number, because 28248991 - 2⁷ = 28248863 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 (28248911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55245 + ... + 55753.

It is an arithmetic number, because the mean of its divisors is an integer number (1958400).

Almost surely, 2^28248991 is an apocalyptic number.

28248991 is a deficient number, since it is larger than the sum of its proper divisors (3085409).

28248991 is a wasteful number, since it uses less digits than its factorization.

28248991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 678.

The product of its digits is 82944, while the sum is 43.

The square root of 28248991 is about 5314.9779867841. The cubic root of 28248991 is about 304.5563414322.

The spelling of 28248991 in words is "twenty-eight million, two hundred forty-eight thousand, nine hundred ninety-one".