28253720 has 64 divisors (see below), whose sum is σ = 69962400. Its totient is φ = 10183680.

The previous prime is 28253713. The next prime is 28253747. The reversal of 28253720 is 2735282.

It is a congruent number.

It is an unprimeable number.

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, 68876 + ... + 69284.

Almost surely, 2^28253720 is an apocalyptic number.

28253720 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 28253720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34981200).

28253720 is an abundant number, since it is smaller than the sum of its proper divisors (41708680).

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

28253720 is a wasteful number, since it uses less digits than its factorization.

28253720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588 (or 584 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 28253720 is about 5315.4228430107. The cubic root of 28253720 is about 304.5733351552.

The spelling of 28253720 in words is "twenty-eight million, two hundred fifty-three thousand, seven hundred twenty".