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280540 = 22513283
BaseRepresentation
bin1000100011111011100
3112020211101
41010133130
532434130
610002444
72245621
oct1043734
9466741
10280540
11181857
12116424
139a900
1474348
15581ca
hex447dc

280540 has 36 divisors (see below), whose sum is σ = 645624. Its totient is φ = 102336.

The previous prime is 280537. The next prime is 280541. The reversal of 280540 is 45082.

It is a happy number.

Together with 365084 it forms an amicable pair .

280540 is a modest number, since divided by 540 gives 280 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3339 + ... + 3421.

It is an arithmetic number, because the mean of its divisors is an integer number (17934).

2280540 is an apocalyptic number.

280540 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 280540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322812).

280540 is an abundant number, since it is smaller than the sum of its proper divisors (365084).

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

280540 is a wasteful number, since it uses less digits than its factorization.

280540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 280540 is about 529.6602684740. The cubic root of 280540 is about 65.4633557632.

It can be divided in two parts, 280 and 540, that added together give a triangular number (820 = T40).

The spelling of 280540 in words is "two hundred eighty thousand, five hundred forty".

Divisors: 1 2 4 5 10 13 20 26 52 65 83 130 166 169 260 332 338 415 676 830 845 1079 1660 1690 2158 3380 4316 5395 10790 14027 21580 28054 56108 70135 140270 280540