641623643 has 4 divisors (see below), whose sum is σ = 652498680. Its totient is φ = 630748608.

The previous prime is 641623607. The next prime is 641623657. The reversal of 641623643 is 346326146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346326146 = 2 ⋅173163073.

It is a cyclic number.

It is not a de Polignac number, because 641623643 - 2²⁴ = 624846427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641623603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5437430 + ... + 5437547.

It is an arithmetic number, because the mean of its divisors is an integer number (163124670).

Almost surely, 2^641623643 is an apocalyptic number.

641623643 is a deficient number, since it is larger than the sum of its proper divisors (10875037).

641623643 is a wasteful number, since it uses less digits than its factorization.

641623643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10875036.

The product of its digits is 62208, while the sum is 35.

The square root of 641623643 is about 25330.2910168833. The cubic root of 641623643 is about 862.5020174426.

Adding to 641623643 its reverse (346326146), we get a palindrome (987949789).

The spelling of 641623643 in words is "six hundred forty-one million, six hundred twenty-three thousand, six hundred forty-three".