28709980 has 48 divisors (see below), whose sum is σ = 67765824. Its totient is φ = 10137600.

The previous prime is 28709977. The next prime is 28709981. The reversal of 28709980 is 8990782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709981) 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, 3580 + ... + 8380.

It is an arithmetic number, because the mean of its divisors is an integer number (1411788).

Almost surely, 2^28709980 is an apocalyptic number.

28709980 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 28709980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33882912).

28709980 is an abundant number, since it is smaller than the sum of its proper divisors (39055844).

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

28709980 is a wasteful number, since it uses less digits than its factorization.

28709980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4846 (or 4844 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 28709980 is about 5358.1694635388. The cubic root of 28709980 is about 306.2040730796.

The spelling of 28709980 in words is "twenty-eight million, seven hundred nine thousand, nine hundred eighty".