643426616 has 32 divisors (see below), whose sum is σ = 1408112640. Its totient is φ = 269886048.

The previous prime is 643426613. The next prime is 643426643. The reversal of 643426616 is 616624346.

It is a happy number.

643426616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×643426616² = 827995620354422912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643426616.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643426613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119600 + ... + 124863.

It is an arithmetic number, because the mean of its divisors is an integer number (44003520).

Almost surely, 2^643426616 is an apocalyptic number.

It is an amenable number.

643426616 is an abundant number, since it is smaller than the sum of its proper divisors (764686024).

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

643426616 is a wasteful number, since it uses less digits than its factorization.

643426616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244523 (or 244519 counting only the distinct ones).

The product of its digits is 124416, while the sum is 38.

The square root of 643426616 is about 25365.8553177298. The cubic root of 643426616 is about 863.3091435243.

The spelling of 643426616 in words is "six hundred forty-three million, four hundred twenty-six thousand, six hundred sixteen".