643277916 has 24 divisors (see below), whose sum is σ = 1667757840. Its totient is φ = 214425936.

The previous prime is 643277911. The next prime is 643277917. The reversal of 643277916 is 619772346.

643277916 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-3 number, since 3×643277916³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643277911) 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, 2978031 + ... + 2978246.

It is an arithmetic number, because the mean of its divisors is an integer number (69489910).

Almost surely, 2^643277916 is an apocalyptic number.

It is an amenable number.

643277916 is an abundant number, since it is smaller than the sum of its proper divisors (1024479924).

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

643277916 is a wasteful number, since it uses less digits than its factorization.

643277916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5956290 (or 5956282 counting only the distinct ones).

The product of its digits is 381024, while the sum is 45.

The square root of 643277916 is about 25362.9240427834. The cubic root of 643277916 is about 863.2426329816.

It can be divided in two parts, 6432 and 77916, that added together give a palindrome (84348).

The spelling of 643277916 in words is "six hundred forty-three million, two hundred seventy-seven thousand, nine hundred sixteen".