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285780 = 223511433
BaseRepresentation
bin1000101110001010100
3112112000110
41011301110
533121110
610043020
72300115
oct1056124
9475013
10285780
11185790
12119470
13a0101
147620c
1559a20
hex45c54

285780 has 48 divisors (see below), whose sum is σ = 874944. Its totient is φ = 69120.

The previous prime is 285773. The next prime is 285781. The reversal of 285780 is 87582.

285780 is nontrivially palindromic in base 16.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285781) by changing a digit.

285780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 444 + ... + 876.

It is an arithmetic number, because the mean of its divisors is an integer number (18228).

2285780 is an apocalyptic number.

285780 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 285780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437472).

285780 is an abundant number, since it is smaller than the sum of its proper divisors (589164).

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

285780 is a wasteful number, since it uses less digits than its factorization.

285780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 285780 is about 534.5839503764. The cubic root of 285780 is about 65.8684247392.

The spelling of 285780 in words is "two hundred eighty-five thousand, seven hundred eighty".

Divisors: 1 2 3 4 5 6 10 11 12 15 20 22 30 33 44 55 60 66 110 132 165 220 330 433 660 866 1299 1732 2165 2598 4330 4763 5196 6495 8660 9526 12990 14289 19052 23815 25980 28578 47630 57156 71445 95260 142890 285780