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128918271 = 342972757
BaseRepresentation
bin1111010111100…
…10001011111111
322222120201121210
413223302023333
5231000341041
620443055503
73123534006
oct753621377
9288521553
10128918271
1166853229
1237211593
132092a301
141319bc3d
15b4b8016
hex7af22ff

128918271 has 4 divisors (see below), whose sum is σ = 171891032. Its totient is φ = 85945512.

The previous prime is 128918269. The next prime is 128918281. The reversal of 128918271 is 172819821.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 128918271 - 21 = 128918269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128918221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21486376 + ... + 21486381.

It is an arithmetic number, because the mean of its divisors is an integer number (42972758).

Almost surely, 2128918271 is an apocalyptic number.

128918271 is a deficient number, since it is larger than the sum of its proper divisors (42972761).

128918271 is an equidigital number, since it uses as much as digits as its factorization.

128918271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42972760.

The product of its digits is 16128, while the sum is 39.

The square root of 128918271 is about 11354.2182029411. The cubic root of 128918271 is about 505.1707046339.

The spelling of 128918271 in words is "one hundred twenty-eight million, nine hundred eighteen thousand, two hundred seventy-one".

Divisors: 1 3 42972757 128918271