2143891 has 4 divisors (see below), whose sum is σ = 2201872. Its totient is φ = 2085912.

The previous prime is 2143877. The next prime is 2143901. The reversal of 2143891 is 1983412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2143891 - 2⁵ = 2143859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2143831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28935 + ... + 29008.

It is an arithmetic number, because the mean of its divisors is an integer number (550468).

2^2143891 is an apocalyptic number.

2143891 is a deficient number, since it is larger than the sum of its proper divisors (57981).

2143891 is an equidigital number, since it uses as much as digits as its factorization.

2143891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57980.

The product of its digits is 1728, while the sum is 28.

The square root of 2143891 is about 1464.2031962812. The cubic root of 2143891 is about 128.9439293207.

It can be divided in two parts, 2 and 143891, that multiplied together give a palindrome (287782).

The spelling of 2143891 in words is "two million, one hundred forty-three thousand, eight hundred ninety-one".