2231891 has 2 divisors, whose sum is σ = 2231892. Its totient is φ = 2231890.

The previous prime is 2231881. The next prime is 2231909. The reversal of 2231891 is 1981322.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2231891 - 2¹⁰ = 2230867 is a prime.

It is a super-3 number, since 3×2231891³ = 33353406573317642913, which contains 333 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2231891.

It is not a weakly prime, because it can be changed into another prime (2231821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1115945 + 1115946.

It is an arithmetic number, because the mean of its divisors is an integer number (1115946).

2^2231891 is an apocalyptic number.

2231891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2231891 is an equidigital number, since it uses as much as digits as its factorization.

2231891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 2231891 is about 1493.9514717687. The cubic root of 2231891 is about 130.6845741400.

It can be divided in two parts, 22 and 31891, that added together give a palindrome (31913).

The spelling of 2231891 in words is "two million, two hundred thirty-one thousand, eight hundred ninety-one".