643544622 has 192 divisors, whose sum is σ = 1789539840. Its totient is φ = 167795712.

The previous prime is 643544609. The next prime is 643544641. The reversal of 643544622 is 226445346.

643544622 is a `hidden beast` number, since 643 + 5 + 4 + 4 + 6 + 2 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4697338 + ... + 4697474.

It is an arithmetic number, because the mean of its divisors is an integer number (9320520).

Almost surely, 2^643544622 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643544622, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894769920).

643544622 is an abundant number, since it is smaller than the sum of its proper divisors (1145995218).

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

643544622 is a wasteful number, since it uses less digits than its factorization.

643544622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 209 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 643544622 is about 25368.1812907429. The cubic root of 643544622 is about 863.3619179609.

Adding to 643544622 its reverse (226445346), we get a palindrome (869989968).

The spelling of 643544622 in words is "six hundred forty-three million, five hundred forty-four thousand, six hundred twenty-two".