28720560 has 240 divisors, whose sum is σ = 104493312. Its totient is φ = 6504960.

The previous prime is 28720553. The next prime is 28720577. The reversal of 28720560 is 6502782.

It is a tau number, because it is divible by the number of its divisors (240).

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 667899 + ... + 667941.

Almost surely, 2^28720560 is an apocalyptic number.

28720560 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 28720560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52246656).

28720560 is an abundant number, since it is smaller than the sum of its proper divisors (75772752).

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

28720560 is a wasteful number, since it uses less digits than its factorization.

28720560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 28720560 is about 5359.1566500710. The cubic root of 28720560 is about 306.2416818510.

The spelling of 28720560 in words is "twenty-eight million, seven hundred twenty thousand, five hundred sixty".