28857280 has 56 divisors (see below), whose sum is σ = 70957440. Its totient is φ = 11166720.

The previous prime is 28857247. The next prime is 28857287. The reversal of 28857280 is 8275882.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28857287) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 8466 + ... + 11374.

Almost surely, 2^28857280 is an apocalyptic number.

28857280 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 28857280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35478720).

28857280 is an abundant number, since it is smaller than the sum of its proper divisors (42100160).

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

28857280 is a wasteful number, since it uses less digits than its factorization.

28857280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2957 (or 2947 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 40.

The square root of 28857280 is about 5371.8972439912. The cubic root of 28857280 is about 306.7268522915.

The spelling of 28857280 in words is "twenty-eight million, eight hundred fifty-seven thousand, two hundred eighty".