643523144 has 32 divisors (see below), whose sum is σ = 1324209600. Its totient is φ = 290752320.

The previous prime is 643523143. The next prime is 643523147. The reversal of 643523144 is 441325346.

It is a self number, because there is not a number n which added to its sum of digits gives 643523144.

It is not an unprimeable number, because it can be changed into a prime (643523143) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7199 + ... + 36590.

It is an arithmetic number, because the mean of its divisors is an integer number (41381550).

Almost surely, 2^643523144 is an apocalyptic number.

It is an amenable number.

643523144 is an abundant number, since it is smaller than the sum of its proper divisors (680686456).

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

643523144 is a wasteful number, since it uses less digits than its factorization.

643523144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43973 (or 43969 counting only the distinct ones).

The product of its digits is 34560, while the sum is 32.

The square root of 643523144 is about 25367.7579616331. The cubic root of 643523144 is about 863.3523130876.

The spelling of 643523144 in words is "six hundred forty-three million, five hundred twenty-three thousand, one hundred forty-four".