2509891 has 2 divisors, whose sum is σ = 2509892. Its totient is φ = 2509890.

The previous prime is 2509861. The next prime is 2509907. The reversal of 2509891 is 1989052.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2509891 - 2⁹ = 2509379 is a prime.

It is not a weakly prime, because it can be changed into another prime (2509811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1254945 + 1254946.

It is an arithmetic number, because the mean of its divisors is an integer number (1254946).

2^2509891 is an apocalyptic number.

2509891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2509891 is an equidigital number, since it uses as much as digits as its factorization.

2509891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 2509891 is about 1584.2635513070. The cubic root of 2509891 is about 135.8996339946.

The spelling of 2509891 in words is "two million, five hundred nine thousand, eight hundred ninety-one".