2991731 has 2 divisors, whose sum is σ = 2991732. Its totient is φ = 2991730.

The previous prime is 2991719. The next prime is 2991733. The reversal of 2991731 is 1371992.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2991731 - 2¹⁰ = 2990707 is a prime.

It is a super-2 number, since 2×2991731² = 17900908752722, which contains 22 as substring.

Together with 2991733, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2991733) 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 as a sum of consecutive naturals, namely, 1495865 + 1495866.

It is an arithmetic number, because the mean of its divisors is an integer number (1495866).

2^2991731 is an apocalyptic number.

2991731 is a deficient number, since it is larger than the sum of its proper divisors (1).

2991731 is an equidigital number, since it uses as much as digits as its factorization.

2991731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 32.

The square root of 2991731 is about 1729.6621057305. The cubic root of 2991731 is about 144.0923244106.

The spelling of 2991731 in words is "two million, nine hundred ninety-one thousand, seven hundred thirty-one".