2003861 has 2 divisors, whose sum is σ = 2003862. Its totient is φ = 2003860.

The previous prime is 2003857. The next prime is 2003863. The reversal of 2003861 is 1683002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1062961 + 940900 = 1031^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 2003861 - 2² = 2003857 is a prime.

It is a Sophie Germain prime.

Together with 2003863, it forms a pair of twin primes.

It is a Chen prime.

2003861 is a modest number, since divided by 3861 gives 2 as remainder.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2003863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1001930 + 1001931.

It is an arithmetic number, because the mean of its divisors is an integer number (1001931).

2^2003861 is an apocalyptic number.

It is an amenable number.

2003861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2003861 is an equidigital number, since it uses as much as digits as its factorization.

2003861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 2003861 is about 1415.5779738326. The cubic root of 2003861 is about 126.0731287926.

Adding to 2003861 its reverse (1683002), we get a palindrome (3686863).

The spelling of 2003861 in words is "two million, three thousand, eight hundred sixty-one".