28712320 has 256 divisors, whose sum is σ = 92534400. Its totient is φ = 8257536.

The previous prime is 28712311. The next prime is 28712339. The reversal of 28712320 is 2321782.

28712320 = 431² + 432² + ... + 549².

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 990066 + ... + 990094.

Almost surely, 2^28712320 is an apocalyptic number.

28712320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

28712320 is the 3094-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28712320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46267200).

28712320 is an abundant number, since it is smaller than the sum of its proper divisors (63822080).

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

28712320 is a wasteful number, since it uses less digits than its factorization.

28712320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 28712320 is about 5358.3878172450. The cubic root of 28712320 is about 306.2123918833.

The spelling of 28712320 in words is "twenty-eight million, seven hundred twelve thousand, three hundred twenty".