2531891 has 2 divisors, whose sum is σ = 2531892. Its totient is φ = 2531890.

The previous prime is 2531869. The next prime is 2531917. The reversal of 2531891 is 1981352.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2531891 - 2¹⁰ = 2530867 is a prime.

It is equal to p₁₈₅₂₅₈ and since 2531891 and 185258 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (2531821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1265945 + 1265946.

It is an arithmetic number, because the mean of its divisors is an integer number (1265946).

2^2531891 is an apocalyptic number.

2531891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2531891 is an equidigital number, since it uses as much as digits as its factorization.

2531891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 29.

The square root of 2531891 is about 1591.1916917832. The cubic root of 2531891 is about 136.2955474352.

The spelling of 2531891 in words is "two million, five hundred thirty-one thousand, eight hundred ninety-one".