28721160 has 288 divisors, whose sum is σ = 112334040. Its totient is φ = 6303744.

The previous prime is 28721137. The next prime is 28721171. The reversal of 28721160 is 6112782.

It can be written as a sum of positive squares in 4 ways, for example, as 21846276 + 6874884 = 4674^2 + 2622^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1511631 + ... + 1511649.

Almost surely, 2^28721160 is an apocalyptic number.

28721160 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 28721160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56167020).

28721160 is an abundant number, since it is smaller than the sum of its proper divisors (83612880).

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

28721160 is a wasteful number, since it uses less digits than its factorization.

28721160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 28721160 is about 5359.2126287357. The cubic root of 28721160 is about 306.2438143968.

The spelling of 28721160 in words is "twenty-eight million, seven hundred twenty-one thousand, one hundred sixty".