2181231 has 24 divisors (see below), whose sum is σ = 3444896. Its totient is φ = 1321920.

The previous prime is 2181229. The next prime is 2181233. The reversal of 2181231 is 1321812.

It is an interprime number because it is at equal distance from previous prime (2181229) and next prime (2181233).

It is not a de Polignac number, because 2181231 - 2¹ = 2181229 is a prime.

It is a super-3 number, since 3×2181231³ = 31133377576579048173, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181233) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11961 + ... + 12141.

2^2181231 is an apocalyptic number.

2181231 is a deficient number, since it is larger than the sum of its proper divisors (1263665).

2181231 is a wasteful number, since it uses less digits than its factorization.

2181231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303 (or 300 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 2181231 is about 1476.8991163922. The cubic root of 2181231 is about 129.6882272471.

The spelling of 2181231 in words is "two million, one hundred eighty-one thousand, two hundred thirty-one".