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BaseRepresentation
bin11111010001100100
320111201110
4133101210
513044400
62425020
71042320
oct372144
9214643
10128100
1188275
1262170
13463cb
1434980
1527e50
hex1f464

128100 has 72 divisors (see below), whose sum is σ = 430528. Its totient is φ = 28800.

The previous prime is 128099. The next prime is 128111. The reversal of 128100 is 1821.

It is a happy number.

It is a super-2 number, since 2×1281002 = 32819220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2070 + ... + 2130.

2128100 is an apocalyptic number.

128100 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 128100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215264).

128100 is an abundant number, since it is smaller than the sum of its proper divisors (302428).

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

128100 is a wasteful number, since it uses less digits than its factorization.

128100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 128100 is about 357.9106033635. The cubic root of 128100 is about 50.4099627571.

Adding to 128100 its reverse (1821), we get a palindrome (129921).

The spelling of 128100 in words is "one hundred twenty-eight thousand, one hundred".