1351643256523 has 4 divisors (see below), whose sum is σ = 1544735150320. Its totient is φ = 1158551362728.

The previous prime is 1351643256517. The next prime is 1351643256529. The reversal of 1351643256523 is 3256523461531.

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

It is an interprime number because it is at equal distance from previous prime (1351643256517) and next prime (1351643256529).

It is a cyclic number.

It is not a de Polignac number, because 1351643256523 - 2²¹ = 1351641159371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1351643256529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96545946888 + ... + 96545946901.

It is an arithmetic number, because the mean of its divisors is an integer number (386183787580).

Almost surely, 2^{1351643256523} is an apocalyptic number.

1351643256523 is a deficient number, since it is larger than the sum of its proper divisors (193091893797).

1351643256523 is an equidigital number, since it uses as much as digits as its factorization.

1351643256523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193091893796.

The product of its digits is 1944000, while the sum is 46.

The spelling of 1351643256523 in words is "one trillion, three hundred fifty-one billion, six hundred forty-three million, two hundred fifty-six thousand, five hundred twenty-three".