2871991 has 2 divisors, whose sum is σ = 2871992. Its totient is φ = 2871990.

The previous prime is 2871971. The next prime is 2872003. The reversal of 2871991 is 1991782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2871991 - 2⁵ = 2871959 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2871991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2871901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1435995 + 1435996.

It is an arithmetic number, because the mean of its divisors is an integer number (1435996).

2^2871991 is an apocalyptic number.

2871991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2871991 is an equidigital number, since it uses as much as digits as its factorization.

2871991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 37.

The square root of 2871991 is about 1694.6949578021. The cubic root of 2871991 is about 142.1437247443.

It can be divided in two parts, 287 and 1991, that added together give a triangular number (2278 = T₆₇).

The spelling of 2871991 in words is "two million, eight hundred seventy-one thousand, nine hundred ninety-one".