643331424 has 24 divisors (see below), whose sum is σ = 1688745240. Its totient is φ = 214443776.

The previous prime is 643331419. The next prime is 643331443. The reversal of 643331424 is 424133346.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×643331424² = 827750642211735552, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 643331391 and 643331400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3350589 + ... + 3350780.

It is an arithmetic number, because the mean of its divisors is an integer number (70364385).

Almost surely, 2^643331424 is an apocalyptic number.

It is an amenable number.

643331424 is an abundant number, since it is smaller than the sum of its proper divisors (1045413816).

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

643331424 is a wasteful number, since it uses less digits than its factorization.

643331424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6701382 (or 6701374 counting only the distinct ones).

The product of its digits is 20736, while the sum is 30.

The square root of 643331424 is about 25363.9788676777. The cubic root of 643331424 is about 863.2665672227.

The spelling of 643331424 in words is "six hundred forty-three million, three hundred thirty-one thousand, four hundred twenty-four".