109721 has 2 divisors, whose sum is σ = 109722. Its totient is φ = 109720.
The previous prime is 109717. The next prime is 109741. The reversal of 109721 is 127901.
It is an a-pointer prime, because the next prime (109741) can be obtained adding 109721 to its sum of digits (20).
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 105625 + 4096 = 325^2 + 64^2 .
It is a cyclic number.
It is not a de Polignac number, because 109721 - 22 = 109717 is a prime.
It is a Chen prime.
It is a plaindrome in base 15.
It is a junction number, because it is equal to n+sod(n) for n = 109693 and 109702.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 109721.
It is not a weakly prime, because it can be changed into another prime (109741) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54860 + 54861.
It is an arithmetic number, because the mean of its divisors is an integer number (54861).
2109721 is an apocalyptic number.
It is an amenable number.
109721 is a deficient number, since it is larger than the sum of its proper divisors (1).
109721 is an equidigital number, since it uses as much as digits as its factorization.
109721 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 126, while the sum is 20.
The square root of 109721 is about 331.2416036672. The cubic root of 109721 is about 47.8736549966.
The spelling of 109721 in words is "one hundred nine thousand, seven hundred twenty-one".
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