643632433405506 has 32 divisors (see below), whose sum is σ = 1430895008332800. Its totient is φ = 214454037687120.

The previous prime is 643632433405463. The next prime is 643632433405519. The reversal of 643632433405506 is 605504334236346.

643632433405506 is a `hidden beast` number, since 6 + 4 + 3 + 6 + 3 + 2 + 43 + 3 + 40 + 550 + 6 = 666.

It is a super-2 number, since 2×643632433405506² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2502836386 + ... + 2503093533.

It is an arithmetic number, because the mean of its divisors is an integer number (44715469010400).

Almost surely, 2^{643632433405506} is an apocalyptic number.

643632433405506 is an abundant number, since it is smaller than the sum of its proper divisors (787262574927294).

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

643632433405506 is a wasteful number, since it uses less digits than its factorization.

643632433405506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5005932311 (or 5005932305 counting only the distinct ones).

The product of its (nonzero) digits is 55987200, while the sum is 54.

The spelling of 643632433405506 in words is "six hundred forty-three trillion, six hundred thirty-two billion, four hundred thirty-three million, four hundred five thousand, five hundred six".