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1388660 = 2257213109
BaseRepresentation
bin101010011000001110100
32121112212212
411103001310
5323414120
645432552
714542400
oct5230164
92545785
101388660
11869359
1256b758
133980c0
14282100
151c66c5
hex153074

1388660 has 72 divisors (see below), whose sum is σ = 3686760. Its totient is φ = 435456.

The previous prime is 1388659. The next prime is 1388669. The reversal of 1388660 is 668831.

It can be divided in two parts, 1388 and 660, that added together give a 11-th power (2048 = 211).

It can be written as a sum of positive squares in 4 ways, for example, as 70756 + 1317904 = 266^2 + 1148^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12686 + ... + 12794.

It is an arithmetic number, because the mean of its divisors is an integer number (51205).

21388660 is an apocalyptic number.

1388660 is a gapful number since it is divisible by the number (10) 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 1388660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1843380).

1388660 is an abundant number, since it is smaller than the sum of its proper divisors (2298100).

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

1388660 is a wasteful number, since it uses less digits than its factorization.

1388660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1388660 is about 1178.4141886451. The cubic root of 1388660 is about 111.5660289797.

The spelling of 1388660 in words is "one million, three hundred eighty-eight thousand, six hundred sixty".

Divisors: 1 2 4 5 7 10 13 14 20 26 28 35 49 52 65 70 91 98 109 130 140 182 196 218 245 260 364 436 455 490 545 637 763 910 980 1090 1274 1417 1526 1820 2180 2548 2834 3052 3185 3815 5341 5668 6370 7085 7630 9919 10682 12740 14170 15260 19838 21364 26705 28340 39676 49595 53410 69433 99190 106820 138866 198380 277732 347165 694330 1388660