1243431331 has 4 divisors (see below), whose sum is σ = 1246678272. Its totient is φ = 1240184392.

The previous prime is 1243431283. The next prime is 1243431337. The reversal of 1243431331 is 1331343421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1331343421 = 4219 ⋅315559.

It is a cyclic number.

It is not a de Polignac number, because 1243431331 - 2²¹ = 1241334179 is a prime.

It is a super-2 number, since 2×1243431331² = 3092242949824863122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1243431296 and 1243431305.

It is not an unprimeable number, because it can be changed into a prime (1243431337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1622896 + ... + 1623661.

It is an arithmetic number, because the mean of its divisors is an integer number (311669568).

Almost surely, 2^1243431331 is an apocalyptic number.

1243431331 is a deficient number, since it is larger than the sum of its proper divisors (3246941).

1243431331 is an equidigital number, since it uses as much as digits as its factorization.

1243431331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3246940.

The product of its digits is 2592, while the sum is 25.

The square root of 1243431331 is about 35262.3216904389. The cubic root of 1243431331 is about 1075.3271277013.

Adding to 1243431331 its reverse (1331343421), we get a palindrome (2574774752).

The spelling of 1243431331 in words is "one billion, two hundred forty-three million, four hundred thirty-one thousand, three hundred thirty-one".