28709520 has 160 divisors (see below), whose sum is σ = 106278912. Its totient is φ = 6268416.

The previous prime is 28709519. The next prime is 28709573. The reversal of 28709520 is 2590782.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38269 + ... + 39011.

Almost surely, 2^28709520 is an apocalyptic number.

28709520 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 28709520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53139456).

28709520 is an abundant number, since it is smaller than the sum of its proper divisors (77569392).

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

28709520 is a wasteful number, since it uses less digits than its factorization.

28709520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789 (or 783 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 28709520 is about 5358.1265382594. The cubic root of 28709520 is about 306.2024377060.

The spelling of 28709520 in words is "twenty-eight million, seven hundred nine thousand, five hundred twenty".