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128801 = 196779
BaseRepresentation
bin11111011100100001
320112200102
4133130201
513110201
62432145
71044341
oct373441
9215612
10128801
1188852
1262655
134681a
1434d21
152826b
hex1f721

128801 has 4 divisors (see below), whose sum is σ = 135600. Its totient is φ = 122004.

The previous prime is 128767. The next prime is 128813. The reversal of 128801 is 108821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-128801 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (128831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3371 + ... + 3408.

It is an arithmetic number, because the mean of its divisors is an integer number (33900).

2128801 is an apocalyptic number.

128801 is the 161-st centered decagonal number.

It is an amenable number.

128801 is a deficient number, since it is larger than the sum of its proper divisors (6799).

128801 is an equidigital number, since it uses as much as digits as its factorization.

128801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6798.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 128801 is about 358.8885620914. Note that the first 3 decimals coincide. The cubic root of 128801 is about 50.5017481341.

Adding to 128801 its sum of digits (20), we get a palindrome (128821).

It can be divided in two parts, 128 and 801, that added together give a palindrome (929).

The spelling of 128801 in words is "one hundred twenty-eight thousand, eight hundred one".

Divisors: 1 19 6779 128801