28029720 has 128 divisors (see below), whose sum is σ = 88646400. Its totient is φ = 7082496.

The previous prime is 28029713. The next prime is 28029811. The reversal of 28029720 is 2792082.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 31 ways as a sum of consecutive naturals, for example, 261907 + ... + 262013.

It is an arithmetic number, because the mean of its divisors is an integer number (692550).

Almost surely, 2^28029720 is an apocalyptic number.

28029720 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 28029720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44323200).

28029720 is an abundant number, since it is smaller than the sum of its proper divisors (60616680).

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

28029720 is a wasteful number, since it uses less digits than its factorization.

28029720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 28029720 is about 5294.3101533628. The cubic root of 28029720 is about 303.7662966074.

The spelling of 28029720 in words is "twenty-eight million, twenty-nine thousand, seven hundred twenty".