2531391 has 4 divisors (see below), whose sum is σ = 3375192. Its totient is φ = 1687592.

The previous prime is 2531387. The next prime is 2531393. The reversal of 2531391 is 1931352.

It is a happy number.

2531391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2531391 - 2² = 2531387 is a prime.

It is a D-number.

2531391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2531393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 421896 + ... + 421901.

It is an arithmetic number, because the mean of its divisors is an integer number (843798).

2^2531391 is an apocalyptic number.

2531391 is a deficient number, since it is larger than the sum of its proper divisors (843801).

2531391 is an equidigital number, since it uses as much as digits as its factorization.

2531391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843800.

The product of its digits is 810, while the sum is 24.

The square root of 2531391 is about 1591.0345690776. The cubic root of 2531391 is about 136.2865749241.

The spelling of 2531391 in words is "two million, five hundred thirty-one thousand, three hundred ninety-one".