643630666253 has 8 divisors (see below), whose sum is σ = 687995453376. Its totient is φ = 600630949600.

The previous prime is 643630666241. The next prime is 643630666279. The reversal of 643630666253 is 352666036346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643630666253 - 2²⁰ = 643629617677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643630666213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341266643 + ... + 341268528.

It is an arithmetic number, because the mean of its divisors is an integer number (85999431672).

Almost surely, 2^643630666253 is an apocalyptic number.

It is an amenable number.

643630666253 is a deficient number, since it is larger than the sum of its proper divisors (44364787123).

643630666253 is a wasteful number, since it uses less digits than its factorization.

643630666253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682535235.

The product of its (nonzero) digits is 8398080, while the sum is 50.

The spelling of 643630666253 in words is "six hundred forty-three billion, six hundred thirty million, six hundred sixty-six thousand, two hundred fifty-three".