28865720 has 32 divisors (see below), whose sum is σ = 69945120. Its totient is φ = 10657920.

The previous prime is 28865663. The next prime is 28865741. The reversal of 28865720 is 2756882.

It is a super-3 number, since 3×28865720³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27236 + ... + 28275.

It is an arithmetic number, because the mean of its divisors is an integer number (2185785).

Almost surely, 2^28865720 is an apocalyptic number.

28865720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28865720 is an abundant number, since it is smaller than the sum of its proper divisors (41079400).

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

28865720 is a wasteful number, since it uses less digits than its factorization.

28865720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55535 (or 55531 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 28865720 is about 5372.6827563146. The cubic root of 28865720 is about 306.7567525719.

The spelling of 28865720 in words is "twenty-eight million, eight hundred sixty-five thousand, seven hundred twenty".