2639891 has 2 divisors, whose sum is σ = 2639892. Its totient is φ = 2639890.

The previous prime is 2639887. The next prime is 2639911. The reversal of 2639891 is 1989362.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2639891 - 2² = 2639887 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2639801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1319945 + 1319946.

It is an arithmetic number, because the mean of its divisors is an integer number (1319946).

2^2639891 is an apocalyptic number.

2639891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2639891 is an equidigital number, since it uses as much as digits as its factorization.

2639891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 38.

The square root of 2639891 is about 1624.7741381497. The cubic root of 2639891 is about 138.2065624626.

The spelling of 2639891 in words is "two million, six hundred thirty-nine thousand, eight hundred ninety-one".