643436860605 has 96 divisors (see below), whose sum is σ = 1298957893632. Its totient is φ = 266223154560.

The previous prime is 643436860567. The next prime is 643436860631. The reversal of 643436860605 is 506068634346.

It is not a de Polignac number, because 643436860605 - 2¹⁴ = 643436844221 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2772484 + ... + 2995586.

It is an arithmetic number, because the mean of its divisors is an integer number (13530811392).

Almost surely, 2^643436860605 is an apocalyptic number.

It is an amenable number.

643436860605 is an abundant number, since it is smaller than the sum of its proper divisors (655521033027).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643436860605 is a wasteful number, since it uses less digits than its factorization.

643436860605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223367 (or 223356 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 51.

The spelling of 643436860605 in words is "six hundred forty-three billion, four hundred thirty-six million, eight hundred sixty thousand, six hundred five".