28145780 has 48 divisors (see below), whose sum is σ = 64331904. Its totient is φ = 10281600.

The previous prime is 28145723. The next prime is 28145791. The reversal of 28145780 is 8754182.

It is a self number, because there is not a number n which added to its sum of digits gives 28145780.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26255 + ... + 27305.

It is an arithmetic number, because the mean of its divisors is an integer number (1340248).

Almost surely, 2^28145780 is an apocalyptic number.

28145780 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 28145780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32165952).

28145780 is an abundant number, since it is smaller than the sum of its proper divisors (36186124).

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

28145780 is a wasteful number, since it uses less digits than its factorization.

28145780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1176 (or 1174 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 28145780 is about 5305.2596543430. The cubic root of 28145780 is about 304.1849780265.

The spelling of 28145780 in words is "twenty-eight million, one hundred forty-five thousand, seven hundred eighty".