643265232503 has 4 divisors (see below), whose sum is σ = 643944499800. Its totient is φ = 642585965208.

The previous prime is 643265232469. The next prime is 643265232529. The reversal of 643265232503 is 305232562346.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643265232503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643265292503) 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, 339632228 + ... + 339634121.

It is an arithmetic number, because the mean of its divisors is an integer number (160986124950).

Almost surely, 2^643265232503 is an apocalyptic number.

643265232503 is a deficient number, since it is larger than the sum of its proper divisors (679267297).

643265232503 is an equidigital number, since it uses as much as digits as its factorization.

643265232503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679267296.

The product of its (nonzero) digits is 777600, while the sum is 41.

Adding to 643265232503 its reverse (305232562346), we get a palindrome (948497794849).

The spelling of 643265232503 in words is "six hundred forty-three billion, two hundred sixty-five million, two hundred thirty-two thousand, five hundred three".