2143861 has 2 divisors, whose sum is σ = 2143862. Its totient is φ = 2143860.

The previous prime is 2143859. The next prime is 2143873. The reversal of 2143861 is 1683412.

2143861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2047761 + 96100 = 1431^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 2143861 - 2¹ = 2143859 is a prime.

It is a super-2 number, since 2×2143861² = 9192279974642, which contains 22 as substring.

Together with 2143859, it forms a pair of twin primes.

It is a d-powerful number, because it can be written as 2²¹ + 1 + 4² + 3³ + 8 + 6⁶ + 1 .

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2143831) 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, 1071930 + 1071931.

It is an arithmetic number, because the mean of its divisors is an integer number (1071931).

2^2143861 is an apocalyptic number.

It is an amenable number.

2143861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2143861 is an equidigital number, since it uses as much as digits as its factorization.

2143861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 2143861 is about 1464.1929517656. The cubic root of 2143861 is about 128.9433278698.

The spelling of 2143861 in words is "two million, one hundred forty-three thousand, eight hundred sixty-one".