1343705257 has 4 divisors (see below), whose sum is σ = 1345738756. Its totient is φ = 1341671760.

The previous prime is 1343705243. The next prime is 1343705263. The reversal of 1343705257 is 7525073431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7525073431 = 37 ⋅203380363.

It can be written as a sum of positive squares in 2 ways, for example, as 799136361 + 544568896 = 28269^2 + 23336^2 .

It is a cyclic number.

It is not a de Polignac number, because 1343705257 - 2²⁷ = 1209487529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1343705267) 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, 1015758 + ... + 1017079.

It is an arithmetic number, because the mean of its divisors is an integer number (336434689).

Almost surely, 2^1343705257 is an apocalyptic number.

It is an amenable number.

1343705257 is a deficient number, since it is larger than the sum of its proper divisors (2033499).

1343705257 is an equidigital number, since it uses as much as digits as its factorization.

1343705257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2033498.

The product of its (nonzero) digits is 88200, while the sum is 37.

The square root of 1343705257 is about 36656.5854520030. The cubic root of 1343705257 is about 1103.4889926715.

Adding to 1343705257 its reverse (7525073431), we get a palindrome (8868778688).

The spelling of 1343705257 in words is "one billion, three hundred forty-three million, seven hundred five thousand, two hundred fifty-seven".