1000861 has 2 divisors, whose sum is σ = 1000862.
Its totient is φ = 1000860.
The previous prime is 1000859. The next prime is 1000889. The reversal of 1000861 is 1680001.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 648025 + 352836 = 805^2 + 594^2
It is a cyclic number.
It is not a de Polignac number, because 1000861 - 21 = 1000859 is a prime.
Together with 1000859, it forms a pair of twin primes.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (1006861) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500430 + 500431.
It is an arithmetic number, because the mean of its divisors is an integer number (500431).
21000861 is an apocalyptic number.
It is an amenable number.
1000861 is a deficient number, since it is larger than the sum of its proper divisors (1).
1000861 is an equidigital number, since it uses as much as digits as its factorization.
1000861 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 48, while the sum is 16.
The square root of 1000861 is about 1000.4304073747.
The cubic root of 1000861 is about 100.0286917670.
Adding to 1000861 its reverse (1680001), we get a palindrome (2680862).
The spelling of 1000861 in words is "one million, eight hundred sixty-one", and thus it is an aban number.