642081440 has 384 divisors, whose sum is σ = 2154055680. Its totient is φ = 174182400.

The previous prime is 642081403. The next prime is 642081463. The reversal of 642081440 is 44180246.

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 63 ways as a sum of consecutive naturals, for example, 3042935 + ... + 3043145.

It is an arithmetic number, because the mean of its divisors is an integer number (5609520).

Almost surely, 2^642081440 is an apocalyptic number.

642081440 is the 14630-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642081440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077027840).

642081440 is an abundant number, since it is smaller than the sum of its proper divisors (1511974240).

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

642081440 is a wasteful number, since it uses less digits than its factorization.

642081440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 642081440 is about 25339.3259578861. The cubic root of 642081440 is about 862.7070997465.

The spelling of 642081440 in words is "six hundred forty-two million, eighty-one thousand, four hundred forty".