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21060013 = 131620001
BaseRepresentation
bin101000001010…
…1100110101101
31110121221220111
41100111212231
520342410023
62031220021
7344002312
oct120254655
943557814
1021060013
1110984777
127077611
134494a60
142b22d09
151cb000d
hex14159ad

21060013 has 4 divisors (see below), whose sum is σ = 22680028. Its totient is φ = 19440000.

The previous prime is 21060001. The next prime is 21060023. The reversal of 21060013 is 31006012.

It is the 1874-th star number.

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 5076009 + 15984004 = 2253^2 + 3998^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-21060013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1620001 = 21060013 / (2 + 1 + 0 + 6 + 0 + 0 + 1 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21059975 and 21060002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060023) 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, 809988 + ... + 810013.

It is an arithmetic number, because the mean of its divisors is an integer number (5670007).

Almost surely, 221060013 is an apocalyptic number.

It is an amenable number.

21060013 is a deficient number, since it is larger than the sum of its proper divisors (1620015).

21060013 is a wasteful number, since it uses less digits than its factorization.

21060013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620014.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21060013 is about 4589.1189786276. The cubic root of 21060013 is about 276.1549792975.

Adding to 21060013 its reverse (31006012), we get a palindrome (52066025).

The spelling of 21060013 in words is "twenty-one million, sixty thousand, thirteen".

Divisors: 1 13 1620001 21060013