861901 has 2 divisors, whose sum is σ = 861902. Its totient is φ = 861900.

The previous prime is 861899. The next prime is 861907. The reversal of 861901 is 109168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 585225 + 276676 = 765^2 + 526^2 .

It is a cyclic number.

It is not a de Polignac number, because 861901 - 2¹ = 861899 is a prime.

Together with 861899, 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 (861907) 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 as a sum of consecutive naturals, namely, 430950 + 430951.

It is an arithmetic number, because the mean of its divisors is an integer number (430951).

2⁸⁶¹⁹⁰¹ is an apocalyptic number.

It is an amenable number.

861901 is a deficient number, since it is larger than the sum of its proper divisors (1).

861901 is an equidigital number, since it uses as much as digits as its factorization.

861901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 861901 is about 928.3862342797. The cubic root of 861901 is about 95.1668719915.

The spelling of 861901 in words is "eight hundred sixty-one thousand, nine hundred one".