643422318 has 64 divisors (see below), whose sum is σ = 1620380160. Its totient is φ = 165456000.

The previous prime is 643422301. The next prime is 643422337. The reversal of 643422318 is 813224346.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39768 + ... + 53556.

It is an arithmetic number, because the mean of its divisors is an integer number (25318440).

Almost surely, 2^643422318 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643422318, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810190080).

643422318 is an abundant number, since it is smaller than the sum of its proper divisors (976957842).

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

643422318 is a wasteful number, since it uses less digits than its factorization.

643422318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13913.

The product of its digits is 27648, while the sum is 33.

The square root of 643422318 is about 25365.7705974015. The cubic root of 643422318 is about 863.3072212585.

The spelling of 643422318 in words is "six hundred forty-three million, four hundred twenty-two thousand, three hundred eighteen".