28030720 has 72 divisors (see below), whose sum is σ = 68433120. Its totient is φ = 10997760.

The previous prime is 28030697. The next prime is 28030747. The reversal of 28030720 is 2703082.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 28030691 and 28030700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77901 + ... + 78259.

It is an arithmetic number, because the mean of its divisors is an integer number (950460).

Almost surely, 2^28030720 is an apocalyptic number.

28030720 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 28030720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34216560).

28030720 is an abundant number, since it is smaller than the sum of its proper divisors (40402400).

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

28030720 is an equidigital number, since it uses as much as digits as its factorization.

28030720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 28030720 is about 5294.4045935308. The cubic root of 28030720 is about 303.7699089955.

The spelling of 28030720 in words is "twenty-eight million, thirty thousand, seven hundred twenty".