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20215 = 513311
BaseRepresentation
bin100111011110111
31000201201
410323313
51121330
6233331
7112636
oct47367
930651
1020215
1114208
12b847
139280
14751d
155eca
hex4ef7

20215 has 8 divisors (see below), whose sum is σ = 26208. Its totient is φ = 14880.

The previous prime is 20201. The next prime is 20219. The reversal of 20215 is 51202.

Adding to 20215 its reverse (51202), we get a palindrome (71417).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20215 - 25 = 20183 is a prime.

20215 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20219) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 91 + ... + 220.

It is an arithmetic number, because the mean of its divisors is an integer number (3276).

220215 is an apocalyptic number.

20215 is a deficient number, since it is larger than the sum of its proper divisors (5993).

20215 is a wasteful number, since it uses less digits than its factorization.

20215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 20215 is about 142.1794640586. The cubic root of 20215 is about 27.2410963252.

The spelling of 20215 in words is "twenty thousand, two hundred fifteen".

Divisors: 1 5 13 65 311 1555 4043 20215