243431131 has 4 divisors (see below), whose sum is σ = 243465264. Its totient is φ = 243397000.

The previous prime is 243431113. The next prime is 243431137. The reversal of 243431131 is 131134342.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 131134342 = 2 ⋅65567171.

It is a cyclic number.

It is not a de Polignac number, because 243431131 - 2²¹ = 241333979 is a prime.

It is a super-2 number, since 2×243431131² = 118517431079878322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243431137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1840 + ... + 22141.

It is an arithmetic number, because the mean of its divisors is an integer number (60866316).

Almost surely, 2^243431131 is an apocalyptic number.

243431131 is a deficient number, since it is larger than the sum of its proper divisors (34133).

243431131 is a wasteful number, since it uses less digits than its factorization.

243431131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34132.

The product of its digits is 864, while the sum is 22.

The square root of 243431131 is about 15602.2796731760. The cubic root of 243431131 is about 624.3939776891.

Adding to 243431131 its reverse (131134342), we get a palindrome (374565473).

It can be divided in two parts, 2434311 and 31, that added together give a palindrome (2434342).

The spelling of 243431131 in words is "two hundred forty-three million, four hundred thirty-one thousand, one hundred thirty-one".