28765440 has 216 divisors, whose sum is σ = 109051488. Its totient is φ = 6942720.

The previous prime is 28765421. The next prime is 28765453. The reversal of 28765440 is 4456782.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28765395 and 28765404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126607 + ... + 126833.

It is an arithmetic number, because the mean of its divisors is an integer number (504868).

Almost surely, 2^28765440 is an apocalyptic number.

28765440 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 28765440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54525744).

28765440 is an abundant number, since it is smaller than the sum of its proper divisors (80286048).

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

28765440 is a wasteful number, since it uses less digits than its factorization.

28765440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 28765440 is about 5363.3422415505. The cubic root of 28765440 is about 306.4011143717.

The spelling of 28765440 in words is "twenty-eight million, seven hundred sixty-five thousand, four hundred forty".