643626216 has 128 divisors (see below), whose sum is σ = 1943040000. Its totient is φ = 196655040.

The previous prime is 643626209. The next prime is 643626229. The reversal of 643626216 is 612626346.

643626216 is a `hidden beast` number, since 6 + 4 + 3 + 626 + 21 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

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, 124695 + ... + 129753.

It is an arithmetic number, because the mean of its divisors is an integer number (15180000).

Almost surely, 2^643626216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643626216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (971520000).

643626216 is an abundant number, since it is smaller than the sum of its proper divisors (1299413784).

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

643626216 is a wasteful number, since it uses less digits than its factorization.

643626216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5124 (or 5114 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 643626216 is about 25369.7894354683. The cubic root of 643626216 is about 863.3984045141.

The spelling of 643626216 in words is "six hundred forty-three million, six hundred twenty-six thousand, two hundred sixteen".