28132720 has 80 divisors (see below), whose sum is σ = 81566208. Its totient is φ = 8766720.

The previous prime is 28132661. The next prime is 28132721. The reversal of 28132720 is 2723182.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28132721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3877 + ... + 8443.

Almost surely, 2^28132720 is an apocalyptic number.

28132720 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 28132720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40783104).

28132720 is an abundant number, since it is smaller than the sum of its proper divisors (53433488).

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

28132720 is a wasteful number, since it uses less digits than its factorization.

28132720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4598 (or 4592 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 28132720 is about 5304.0286575395. The cubic root of 28132720 is about 304.1379221810.

The spelling of 28132720 in words is "twenty-eight million, one hundred thirty-two thousand, seven hundred twenty".