28865780 has 24 divisors (see below), whose sum is σ = 60726120. Its totient is φ = 11525760.

The previous prime is 28865773. The next prime is 28865791. The reversal of 28865780 is 8756882.

It can be written as a sum of positive squares in 4 ways, for example, as 7396 + 28858384 = 86^2 + 5372^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15710 + ... + 17450.

It is an arithmetic number, because the mean of its divisors is an integer number (2530255).

Almost surely, 2^28865780 is an apocalyptic number.

28865780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28865780 is an abundant number, since it is smaller than the sum of its proper divisors (31860340).

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

28865780 is a wasteful number, since it uses less digits than its factorization.

28865780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2579 (or 2577 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 28865780 is about 5372.6883401143. The cubic root of 28865780 is about 306.7569651123.

The spelling of 28865780 in words is "twenty-eight million, eight hundred sixty-five thousand, seven hundred eighty".