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12890000 = 24541289
BaseRepresentation
bin110001001010…
…111110010000
3220020212202102
4301022332100
511244440000
61140135532
7214364114
oct61127620
926225672
1012890000
1173044a2
1243975a8
132894126
1419d7744
1511e93d5
hexc4af90

12890000 has 50 divisors (see below), whose sum is σ = 31232190. Its totient is φ = 5152000.

The previous prime is 12889997. The next prime is 12890027. The reversal of 12890000 is 9821.

It can be written as a sum of positive squares in 5 ways, for example, as 3055504 + 9834496 = 1748^2 + 3136^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 9356 + ... + 10644.

Almost surely, 212890000 is an apocalyptic number.

12890000 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 12890000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15616095).

12890000 is an abundant number, since it is smaller than the sum of its proper divisors (18342190).

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

12890000 is an equidigital number, since it uses as much as digits as its factorization.

12890000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317 (or 1296 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 12890000 is about 3590.2646142032. The cubic root of 12890000 is about 234.4683924102.

Adding to 12890000 its reverse (9821), we get a palindrome (12899821).

The spelling of 12890000 in words is "twelve million, eight hundred ninety thousand".

Divisors: 1 2 4 5 8 10 16 20 25 40 50 80 100 125 200 250 400 500 625 1000 1250 1289 2000 2500 2578 5000 5156 6445 10000 10312 12890 20624 25780 32225 51560 64450 103120 128900 161125 257800 322250 515600 644500 805625 1289000 1611250 2578000 3222500 6445000 12890000