28199724 has 48 divisors (see below), whose sum is σ = 79161600. Its totient is φ = 7632576.

The previous prime is 28199723. The next prime is 28199729. The reversal of 28199724 is 42799182.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (28199723) 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 15 ways as a sum of consecutive naturals, for example, 7239 + ... + 10430.

It is an arithmetic number, because the mean of its divisors is an integer number (1649200).

Almost surely, 2^28199724 is an apocalyptic number.

It is an amenable number.

28199724 is an abundant number, since it is smaller than the sum of its proper divisors (50961876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28199724 is a wasteful number, since it uses less digits than its factorization.

28199724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17702 (or 17700 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 28199724 is about 5310.3412319737. The cubic root of 28199724 is about 304.3791869216.

The spelling of 28199724 in words is "twenty-eight million, one hundred ninety-nine thousand, seven hundred twenty-four".