643624403 has 4 divisors (see below), whose sum is σ = 681484680. Its totient is φ = 605764128.

The previous prime is 643624381. The next prime is 643624427. The reversal of 643624403 is 304426346.

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

It is a de Polignac number, because none of the positive numbers 2^k-643624403 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 643624403.

It is not an unprimeable number, because it can be changed into a prime (643624453) 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, 18930113 + ... + 18930146.

It is an arithmetic number, because the mean of its divisors is an integer number (170371170).

Almost surely, 2^643624403 is an apocalyptic number.

643624403 is a deficient number, since it is larger than the sum of its proper divisors (37860277).

643624403 is a wasteful number, since it uses less digits than its factorization.

643624403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37860276.

The product of its (nonzero) digits is 41472, while the sum is 32.

The square root of 643624403 is about 25369.7537039680. The cubic root of 643624403 is about 863.3975938248.

The spelling of 643624403 in words is "six hundred forty-three million, six hundred twenty-four thousand, four hundred three".