643263503 has 4 divisors (see below), whose sum is σ = 643784760. Its totient is φ = 642742248.

The previous prime is 643263497. The next prime is 643263521. The reversal of 643263503 is 305362346.

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 643263503 - 2¹⁰ = 643262479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643263503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643265503) 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, 258773 + ... + 261246.

It is an arithmetic number, because the mean of its divisors is an integer number (160946190).

Almost surely, 2^643263503 is an apocalyptic number.

643263503 is a deficient number, since it is larger than the sum of its proper divisors (521257).

643263503 is a wasteful number, since it uses less digits than its factorization.

643263503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521256.

The product of its (nonzero) digits is 38880, while the sum is 32.

The square root of 643263503 is about 25362.6399059719. The cubic root of 643263503 is about 863.2361857895.

The spelling of 643263503 in words is "six hundred forty-three million, two hundred sixty-three thousand, five hundred three".