Base | Representation |
---|---|
bin | 10100000010000110… |
… | …010101100010010101 |
3 | 2001112001221212011012 |
4 | 110002012111202111 |
5 | 323023033130424 |
6 | 13514231022005 |
7 | 1361016265556 |
oct | 240206254225 |
9 | 61461855135 |
10 | 21510051989 |
11 | 9138955478 |
12 | 420380a905 |
13 | 204a4a931a |
14 | 1080a8432d |
15 | 85d5edb0e |
hex | 502195895 |
21510051989 has 2 divisors, whose sum is σ = 21510051990. Its totient is φ = 21510051988.
The previous prime is 21510051949. The next prime is 21510052001. The reversal of 21510051989 is 98915001512.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 18211502500 + 3298549489 = 134950^2 + 57433^2 .
It is a cyclic number.
It is not a de Polignac number, because 21510051989 - 28 = 21510051733 is a prime.
It is a super-2 number, since 2×215100519892 (a number of 21 digits) contains 22 as substring.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (21510051919) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10755025994 + 10755025995.
It is an arithmetic number, because the mean of its divisors is an integer number (10755025995).
Almost surely, 221510051989 is an apocalyptic number.
It is an amenable number.
21510051989 is a deficient number, since it is larger than the sum of its proper divisors (1).
21510051989 is an equidigital number, since it uses as much as digits as its factorization.
21510051989 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 32400, while the sum is 41.
The spelling of 21510051989 in words is "twenty-one billion, five hundred ten million, fifty-one thousand, nine hundred eighty-nine".
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