2231391 has 16 divisors (see below), whose sum is σ = 3154176. Its totient is φ = 1400256.

The previous prime is 2231389. The next prime is 2231407. The reversal of 2231391 is 1931322.

It is a happy number.

It is not a de Polignac number, because 2231391 - 2¹ = 2231389 is a prime.

It is a super-3 number, since 3×2231391³ = 33330995576235928413, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2231311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4816 + ... + 5258.

It is an arithmetic number, because the mean of its divisors is an integer number (197136).

2^2231391 is an apocalyptic number.

2231391 is a deficient number, since it is larger than the sum of its proper divisors (922785).

2231391 is a wasteful number, since it uses less digits than its factorization.

2231391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542.

The product of its digits is 324, while the sum is 21.

The square root of 2231391 is about 1493.7841209492. The cubic root of 2231391 is about 130.6748145285.

It can be divided in two parts, 22 and 31391, that added together give a palindrome (31413).

The spelling of 2231391 in words is "two million, two hundred thirty-one thousand, three hundred ninety-one".