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21415 = 54283
BaseRepresentation
bin101001110100111
31002101011
411032213
51141130
6243051
7116302
oct51647
932334
1021415
11150a9
1210487
139994
147b39
15652a
hex53a7

21415 has 4 divisors (see below), whose sum is σ = 25704. Its totient is φ = 17128.

The previous prime is 21407. The next prime is 21419. The reversal of 21415 is 51412.

21415 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 21415 - 23 = 21407 is a prime.

It is a Duffinian number.

21415 is strictly pandigital in base 6.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 21395 and 21404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21419) 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, 2137 + ... + 2146.

It is an arithmetic number, because the mean of its divisors is an integer number (6426).

221415 is an apocalyptic number.

21415 is a deficient number, since it is larger than the sum of its proper divisors (4289).

21415 is an equidigital number, since it uses as much as digits as its factorization.

21415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4288.

The product of its digits is 40, while the sum is 13.

The square root of 21415 is about 146.3386483469. The cubic root of 21415 is about 27.7697962254.

Adding to 21415 its reverse (51412), we get a palindrome (72827).

The spelling of 21415 in words is "twenty-one thousand, four hundred fifteen".

Divisors: 1 5 4283 21415