28780560 has 120 divisors (see below), whose sum is σ = 98190144. Its totient is φ = 7553280.

The previous prime is 28780559. The next prime is 28780571. The reversal of 28780560 is 6508782.

28780560 is a `hidden beast` number, since 28 + 78 + 0 + 560 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50839 + ... + 51401.

Almost surely, 2^28780560 is an apocalyptic number.

28780560 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 28780560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49095072).

28780560 is an abundant number, since it is smaller than the sum of its proper divisors (69409584).

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

28780560 is a wasteful number, since it uses less digits than its factorization.

28780560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 644 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 28780560 is about 5364.7516251920. The cubic root of 28780560 is about 306.4547895849.

The spelling of 28780560 in words is "twenty-eight million, seven hundred eighty thousand, five hundred sixty".