2578391 has 2 divisors, whose sum is σ = 2578392. Its totient is φ = 2578390.

The previous prime is 2578351. The next prime is 2578393. The reversal of 2578391 is 1938752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2578391 - 2¹⁸ = 2316247 is a prime.

It is a Sophie Germain prime.

Together with 2578393, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2578393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1289195 + 1289196.

It is an arithmetic number, because the mean of its divisors is an integer number (1289196).

2^2578391 is an apocalyptic number.

2578391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2578391 is an equidigital number, since it uses as much as digits as its factorization.

2578391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 35.

The square root of 2578391 is about 1605.7369024843. The cubic root of 2578391 is about 137.1248794742.

The spelling of 2578391 in words is "two million, five hundred seventy-eight thousand, three hundred ninety-one".