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21168005 = 54233601
BaseRepresentation
bin101000010111…
…1111110000101
31110211110001012
41100233332011
520404334010
62033412005
7344632205
oct120577605
943743035
1021168005
1110a48921
12710a005
134501c61
142b50405
151cd2005
hex142ff85

21168005 has 4 divisors (see below), whose sum is σ = 25401612. Its totient is φ = 16934400.

The previous prime is 21167989. The next prime is 21168023. The reversal of 21168005 is 50086112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3334276 + 17833729 = 1826^2 + 4223^2 .

It is not a de Polignac number, because 21168005 - 24 = 21167989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2116796 + ... + 2116805.

It is an arithmetic number, because the mean of its divisors is an integer number (6350403).

Almost surely, 221168005 is an apocalyptic number.

It is an amenable number.

21168005 is a deficient number, since it is larger than the sum of its proper divisors (4233607).

21168005 is an equidigital number, since it uses as much as digits as its factorization.

21168005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233606.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 21168005 is about 4600.8700264189. The cubic root of 21168005 is about 276.6261993037.

The spelling of 21168005 in words is "twenty-one million, one hundred sixty-eight thousand, five".

Divisors: 1 5 4233601 21168005