231145 has 4 divisors (see below), whose sum is σ = 277380. Its totient is φ = 184912.

The previous prime is 231131. The next prime is 231169. The reversal of 231145 is 541132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 183184 + 47961 = 428^2 + 219^2 .

It is a cyclic number.

It is not a de Polignac number, because 231145 - 2⁷ = 231017 is a prime.

It is a super-2 number, since 2×231145² = 106856022050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23110 + ... + 23119.

It is an arithmetic number, because the mean of its divisors is an integer number (69345).

2²³¹¹⁴⁵ is an apocalyptic number.

It is an amenable number.

231145 is a deficient number, since it is larger than the sum of its proper divisors (46235).

231145 is an equidigital number, since it uses as much as digits as its factorization.

231145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46234.

The product of its digits is 120, while the sum is 16.

The square root of 231145 is about 480.7754153448. The cubic root of 231145 is about 61.3707599495.

Adding to 231145 its reverse (541132), we get a palindrome (772277).

It can be divided in two parts, 23 and 1145, that multiplied together give a triangular number (26335 = T₂₂₉).

The spelling of 231145 in words is "two hundred thirty-one thousand, one hundred forty-five".