28056780 has 144 divisors (see below), whose sum is σ = 92461824. Its totient is φ = 7128000.

The previous prime is 28056773. The next prime is 28056797. The reversal of 28056780 is 8765082.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 111655 + ... + 111905.

It is an arithmetic number, because the mean of its divisors is an integer number (642096).

Almost surely, 2^28056780 is an apocalyptic number.

28056780 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 28056780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46230912).

28056780 is an abundant number, since it is smaller than the sum of its proper divisors (64405044).

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

28056780 is a wasteful number, since it uses less digits than its factorization.

28056780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 28056780 is about 5296.8651106102. The cubic root of 28056780 is about 303.8640175529.

The spelling of 28056780 in words is "twenty-eight million, fifty-six thousand, seven hundred eighty".