28724580 has 144 divisors (see below), whose sum is σ = 94610880. Its totient is φ = 7029504.

The previous prime is 28724503. The next prime is 28724581. The reversal of 28724580 is 8542782.

It is a happy number.

28724580 is a `hidden beast` number, since 2 + 8 + 72 + 4 + 580 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28724581) 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 47 ways as a sum of consecutive naturals, for example, 126427 + ... + 126653.

It is an arithmetic number, because the mean of its divisors is an integer number (657020).

Almost surely, 2^28724580 is an apocalyptic number.

28724580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28724580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47305440).

28724580 is an abundant number, since it is smaller than the sum of its proper divisors (65886300).

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

28724580 is a wasteful number, since it uses less digits than its factorization.

28724580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 28724580 is about 5359.5316959600. The cubic root of 28724580 is about 306.2559693408.

The spelling of 28724580 in words is "twenty-eight million, seven hundred twenty-four thousand, five hundred eighty".