1243705313 has 4 divisors (see below), whose sum is σ = 1257679620. Its totient is φ = 1229731008.

The previous prime is 1243705301. The next prime is 1243705319. The reversal of 1243705313 is 3135073421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3135073421 = 6869 ⋅456409.

It can be written as a sum of positive squares in 2 ways, for example, as 664195984 + 579509329 = 25772^2 + 24073^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243705313 is a prime.

It is a super-3 number, since 3×1243705313³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1243705319) 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, 6987020 + ... + 6987197.

It is an arithmetic number, because the mean of its divisors is an integer number (314419905).

Almost surely, 2^1243705313 is an apocalyptic number.

It is an amenable number.

1243705313 is a deficient number, since it is larger than the sum of its proper divisors (13974307).

1243705313 is an equidigital number, since it uses as much as digits as its factorization.

1243705313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13974306.

The product of its (nonzero) digits is 7560, while the sum is 29.

The square root of 1243705313 is about 35266.2063879857. The cubic root of 1243705313 is about 1075.4061023454.

Adding to 1243705313 its reverse (3135073421), we get a palindrome (4378778734).

The spelling of 1243705313 in words is "one billion, two hundred forty-three million, seven hundred five thousand, three hundred thirteen".