Base | Representation |
---|---|
bin | 101000000011… |
… | …1100010110101 |
3 | 1110112000220110 |
4 | 1100013202311 |
5 | 20334034141 |
6 | 2030053233 |
7 | 343342356 |
oct | 120074265 |
9 | 43460813 |
10 | 21002421 |
11 | 10945480 |
12 | 704a219 |
13 | 447478b |
14 | 2b09d2d |
15 | 1c9ce16 |
hex | 14078b5 |
21002421 has 32 divisors (see below), whose sum is σ = 31868928. Its totient is φ = 12191040.
The previous prime is 21002413. The next prime is 21002431. The reversal of 21002421 is 12420012.
It is not a de Polignac number, because 21002421 - 23 = 21002413 is a prime.
It is a super-2 number, since 2×210024212 = 882203375722482, which contains 22 as substring.
It is a Curzon number.
It is a junction number, because it is equal to n+sod(n) for n = 21002397 and 21002406.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (21002431) 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 31 ways as a sum of consecutive naturals, for example, 125680 + ... + 125846.
It is an arithmetic number, because the mean of its divisors is an integer number (995904).
Almost surely, 221002421 is an apocalyptic number.
It is an amenable number.
21002421 is a deficient number, since it is larger than the sum of its proper divisors (10866507).
21002421 is a wasteful number, since it uses less digits than its factorization.
21002421 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 321.
The product of its (nonzero) digits is 32, while the sum is 12.
The square root of 21002421 is about 4582.8398400991. The cubic root of 21002421 is about 275.9030193822.
Adding to 21002421 its reverse (12420012), we get a palindrome (33422433).
The spelling of 21002421 in words is "twenty-one million, two thousand, four hundred twenty-one".
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