2861 has 2 divisors, whose sum is σ = 2862. Its totient is φ = 2860.
The previous prime is 2857. The next prime is 2879. The reversal of 2861 is 1682.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 2500 + 361 = 50^2 + 19^2 .
It is a cyclic number.
It is not a de Polignac number, because 2861 - 22 = 2857 is a prime.
It is a Chen prime.
It is a plaindrome in base 7.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2801) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1430 + 1431.
It is an arithmetic number, because the mean of its divisors is an integer number (1431).
22861 is an apocalyptic number.
It is an amenable number.
2861 is a deficient number, since it is larger than the sum of its proper divisors (1).
2861 is an equidigital number, since it uses as much as digits as its factorization.
2861 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 96, while the sum is 17.
The square root of 2861 is about 53.4883164813. The cubic root of 2861 is about 14.1962166738.
The spelling of 2861 in words is "two thousand, eight hundred sixty-one".
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