201231 has 16 divisors (see below), whose sum is σ = 309600. Its totient is φ = 129024.

The previous prime is 201211. The next prime is 201233. The reversal of 201231 is 132102.

201231 = T₂₆ + T₂₇ + ... + T₁₀₆.

It is a happy number.

It is not a de Polignac number, because 201231 - 2⁶ = 201167 is a prime.

It is a super-2 number, since 2×201231² = 80987830722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

201231 is a lucky number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201233) 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, 655 + ... + 911.

It is an arithmetic number, because the mean of its divisors is an integer number (19350).

2²⁰¹²³¹ is an apocalyptic number.

201231 is a deficient number, since it is larger than the sum of its proper divisors (108369).

201231 is a wasteful number, since it uses less digits than its factorization.

201231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 201231 is about 448.5877840512. The cubic root of 201231 is about 58.6000916336.

Adding to 201231 its reverse (132102), we get a palindrome (333333).

The spelling of 201231 in words is "two hundred one thousand, two hundred thirty-one".