1340404243 has 4 divisors (see below), whose sum is σ = 1359283248. Its totient is φ = 1321525240.

The previous prime is 1340404237. The next prime is 1340404259. The reversal of 1340404243 is 3424040431.

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

It is a cyclic number.

It is not a de Polignac number, because 1340404243 - 2¹⁷ = 1340273171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1340404843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9439396 + ... + 9439537.

It is an arithmetic number, because the mean of its divisors is an integer number (339820812).

Almost surely, 2^1340404243 is an apocalyptic number.

1340404243 is a deficient number, since it is larger than the sum of its proper divisors (18879005).

1340404243 is an equidigital number, since it uses as much as digits as its factorization.

1340404243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18879004.

The product of its (nonzero) digits is 4608, while the sum is 25.

The square root of 1340404243 is about 36611.5315576937. The cubic root of 1340404243 is about 1102.5846228171.

Adding to 1340404243 its reverse (3424040431), we get a palindrome (4764444674).

The spelling of 1340404243 in words is "one billion, three hundred forty million, four hundred four thousand, two hundred forty-three".