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20515 = 511373
BaseRepresentation
bin101000000100011
31001010211
411000203
51124030
6234551
7113545
oct50043
931124
1020515
1114460
12ba57
139451
147695
15612a
hex5023

20515 has 8 divisors (see below), whose sum is σ = 26928. Its totient is φ = 14880.

The previous prime is 20509. The next prime is 20521. The reversal of 20515 is 51502.

20515 = 16 + 26 + ... + 56.

It is an interprime number because it is at equal distance from previous prime (20509) and next prime (20521).

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

It is not a de Polignac number, because 20515 - 23 = 20507 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20495 and 20504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132 + ... + 241.

It is an arithmetic number, because the mean of its divisors is an integer number (3366).

220515 is an apocalyptic number.

20515 is a deficient number, since it is larger than the sum of its proper divisors (6413).

20515 is a wasteful number, since it uses less digits than its factorization.

20515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389.

The product of its (nonzero) digits is 50, while the sum is 13.

The square root of 20515 is about 143.2305833263. The cubic root of 20515 is about 27.3751919949.

Subtracting from 20515 its sum of digits (13), we obtain a palindrome (20502).

It can be divided in two parts, 20 and 515, that added together give a palindrome (535).

The spelling of 20515 in words is "twenty thousand, five hundred fifteen".

Divisors: 1 5 11 55 373 1865 4103 20515