643765659492 has 24 divisors (see below), whose sum is σ = 1502136237952. Its totient is φ = 214586215200.

The previous prime is 643765659473. The next prime is 643765659497. The reversal of 643765659492 is 294956567346.

It is not an unprimeable number, because it can be changed into a prime (643765659497) 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, 1133142 + ... + 1603602.

Almost surely, 2^643765659492 is an apocalyptic number.

It is an amenable number.

643765659492 is an abundant number, since it is smaller than the sum of its proper divisors (858370578460).

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

643765659492 is a wasteful number, since it uses less digits than its factorization.

643765659492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584499 (or 584497 counting only the distinct ones).

The product of its digits is 293932800, while the sum is 66.

The spelling of 643765659492 in words is "six hundred forty-three billion, seven hundred sixty-five million, six hundred fifty-nine thousand, four hundred ninety-two".