645203375243 has 4 divisors (see below), whose sum is σ = 737375286000. Its totient is φ = 553031464488.

The previous prime is 645203375227. The next prime is 645203375269. The reversal of 645203375243 is 342573302546.

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 645203375243 - 2⁴ = 645203375227 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645203375194 and 645203375203.

It is not an unprimeable number, because it can be changed into a prime (645203374243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46085955368 + ... + 46085955381.

It is an arithmetic number, because the mean of its divisors is an integer number (184343821500).

Almost surely, 2^645203375243 is an apocalyptic number.

645203375243 is a deficient number, since it is larger than the sum of its proper divisors (92171910757).

645203375243 is an equidigital number, since it uses as much as digits as its factorization.

645203375243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92171910756.

The product of its (nonzero) digits is 1814400, while the sum is 44.

Adding to 645203375243 its reverse (342573302546), we get a palindrome (987776677789).

The spelling of 645203375243 in words is "six hundred forty-five billion, two hundred three million, three hundred seventy-five thousand, two hundred forty-three".