643842342 has 144 divisors (see below), whose sum is σ = 1677252096. Its totient is φ = 176904000.

The previous prime is 643842319. The next prime is 643842361. The reversal of 643842342 is 243248346.

643842342 is a `hidden beast` number, since 643 + 8 + 4 + 2 + 3 + 4 + 2 = 666.

It is a super-3 number, since 3×643842342³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 643842297 and 643842306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2375667 + ... + 2375937.

It is an arithmetic number, because the mean of its divisors is an integer number (11647584).

Almost surely, 2^643842342 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643842342, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (838626048).

643842342 is an abundant number, since it is smaller than the sum of its proper divisors (1033409754).

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

643842342 is a wasteful number, since it uses less digits than its factorization.

643842342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 371 counting only the distinct ones).

The product of its digits is 110592, while the sum is 36.

The square root of 643842342 is about 25374.0485930015. The cubic root of 643842342 is about 863.4950351133.

The spelling of 643842342 in words is "six hundred forty-three million, eight hundred forty-two thousand, three hundred forty-two".