643235052020 has 48 divisors (see below), whose sum is σ = 1494347895936. Its totient is φ = 230609232000.

The previous prime is 643235052011. The next prime is 643235052023. The reversal of 643235052020 is 20250532346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643235052023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20574491 + ... + 20605730.

It is an arithmetic number, because the mean of its divisors is an integer number (31132247832).

Almost surely, 2^643235052020 is an apocalyptic number.

It is an amenable number.

643235052020 is an abundant number, since it is smaller than the sum of its proper divisors (851112843916).

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

643235052020 is a wasteful number, since it uses less digits than its factorization.

643235052020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41180312 (or 41180310 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 32.

Adding to 643235052020 its reverse (20250532346), we get a palindrome (663485584366).

The spelling of 643235052020 in words is "six hundred forty-three billion, two hundred thirty-five million, fifty-two thousand, twenty".