642944544 has 96 divisors (see below), whose sum is σ = 1862118720. Its totient is φ = 192614400.

The previous prime is 642944531. The next prime is 642944569. The reversal of 642944544 is 445449246.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 642944496 and 642944505.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90564 + ... + 97404.

It is an arithmetic number, because the mean of its divisors is an integer number (19397070).

Almost surely, 2^642944544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642944544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (931059360).

642944544 is an abundant number, since it is smaller than the sum of its proper divisors (1219174176).

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

642944544 is a wasteful number, since it uses less digits than its factorization.

642944544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6954 (or 6946 counting only the distinct ones).

The product of its digits is 552960, while the sum is 42.

The square root of 642944544 is about 25356.3511570573. The cubic root of 642944544 is about 863.0934850818.

The spelling of 642944544 in words is "six hundred forty-two million, nine hundred forty-four thousand, five hundred forty-four".