2631891 has 4 divisors (see below), whose sum is σ = 3509192. Its totient is φ = 1754592.

The previous prime is 2631887. The next prime is 2631917. The reversal of 2631891 is 1981362.

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

It is not a de Polignac number, because 2631891 - 2² = 2631887 is a prime.

It is a D-number.

It is a Duffinian number.

2631891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2631851) 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, 438646 + ... + 438651.

It is an arithmetic number, because the mean of its divisors is an integer number (877298).

2^2631891 is an apocalyptic number.

2631891 is a deficient number, since it is larger than the sum of its proper divisors (877301).

2631891 is an equidigital number, since it uses as much as digits as its factorization.

2631891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 877300.

The product of its digits is 2592, while the sum is 30.

The square root of 2631891 is about 1622.3103895371. The cubic root of 2631891 is about 138.0668128479.

The spelling of 2631891 in words is "two million, six hundred thirty-one thousand, eight hundred ninety-one".