2781871 has 4 divisors (see below), whose sum is σ = 2785552. Its totient is φ = 2778192.

The previous prime is 2781853. The next prime is 2781887. The reversal of 2781871 is 1781872.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2781871 - 2⁷ = 2781743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246 + ... + 2371.

It is an arithmetic number, because the mean of its divisors is an integer number (696388).

2^2781871 is an apocalyptic number.

2781871 is a deficient number, since it is larger than the sum of its proper divisors (3681).

2781871 is a wasteful number, since it uses less digits than its factorization.

2781871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3680.

The product of its digits is 6272, while the sum is 34.

The square root of 2781871 is about 1667.8941812957. The cubic root of 2781871 is about 140.6411241429.

Subtracting from 2781871 its reverse (1781872), we obtain a palindrome (999999).

It can be divided in two parts, 27818 and 71, that multiplied together give a triangular number (1975078 = T₁₉₈₇).

The spelling of 2781871 in words is "two million, seven hundred eighty-one thousand, eight hundred seventy-one".