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16815 = 351959
BaseRepresentation
bin100000110101111
3212001210
410012233
51014230
6205503
7100011
oct40657
925053
1016815
11116a7
129893
137866
1461b1
154eb0
hex41af

16815 has 16 divisors (see below), whose sum is σ = 28800. Its totient is φ = 8352.

The previous prime is 16811. The next prime is 16823. The reversal of 16815 is 51861.

Adding to 16815 its sum of digits (21), we get a triangular number (16836 = T183).

16815 is digitally balanced in base 3 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16815 - 22 = 16811 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16791 and 16800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256 + ... + 314.

It is an arithmetic number, because the mean of its divisors is an integer number (1800).

16815 is a Friedman number, since it can be written as 8+(6+1)^(5*1), using all its digits and the basic arithmetic operations.

216815 is an apocalyptic number.

16815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

16815 is a deficient number, since it is larger than the sum of its proper divisors (11985).

16815 is a wasteful number, since it uses less digits than its factorization.

16815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86.

The product of its digits is 240, while the sum is 21.

The square root of 16815 is about 129.6726648141. The cubic root of 16815 is about 25.6192035273.

The spelling of 16815 in words is "sixteen thousand, eight hundred fifteen".