2781943 has 4 divisors (see below), whose sum is σ = 2788720. Its totient is φ = 2775168.

The previous prime is 2781937. The next prime is 2781949. The reversal of 2781943 is 3491872.

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

It is an interprime number because it is at equal distance from previous prime (2781937) and next prime (2781949).

It is a cyclic number.

It is not a de Polignac number, because 2781943 - 2²¹ = 684791 is a prime.

It is a Duffinian number.

2781943 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2781899 and 2781908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781949) 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, 2730 + ... + 3607.

It is an arithmetic number, because the mean of its divisors is an integer number (697180).

2^2781943 is an apocalyptic number.

2781943 is a deficient number, since it is larger than the sum of its proper divisors (6777).

2781943 is an equidigital number, since it uses as much as digits as its factorization.

2781943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6776.

The product of its digits is 12096, while the sum is 34.

The square root of 2781943 is about 1667.9157652591. The cubic root of 2781943 is about 140.6423374838.

The spelling of 2781943 in words is "two million, seven hundred eighty-one thousand, nine hundred forty-three".