643511412 has 24 divisors (see below), whose sum is σ = 1668363200. Its totient is φ = 214503768.

The previous prime is 643511389. The next prime is 643511417. The reversal of 643511412 is 214115346.

It is a happy number.

643511412 is a `hidden beast` number, since 643 + 5 + 1 + 1 + 4 + 12 = 666.

643511412 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643511417) 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, 2979112 + ... + 2979327.

Almost surely, 2^643511412 is an apocalyptic number.

It is an amenable number.

643511412 is an abundant number, since it is smaller than the sum of its proper divisors (1024851788).

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

643511412 is a wasteful number, since it uses less digits than its factorization.

643511412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5958452 (or 5958444 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 643511412 is about 25367.5267221698. The cubic root of 643511412 is about 863.3470664953.

Adding to 643511412 its reverse (214115346), we get a palindrome (857626758).

The spelling of 643511412 in words is "six hundred forty-three million, five hundred eleven thousand, four hundred twelve".