642556800 has 480 divisors, whose sum is σ = 2471608920. Its totient is φ = 164229120.

The previous prime is 642556777. The next prime is 642556861. The reversal of 642556800 is 8655246.

642556800 is a `hidden beast` number, since 642 + 5 + 5 + 6 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 59 ways as a sum of consecutive naturals, for example, 9590367 + ... + 9590433.

Almost surely, 2^642556800 is an apocalyptic number.

642556800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642556800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1235804460).

642556800 is an abundant number, since it is smaller than the sum of its proper divisors (1829052120).

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

642556800 is a wasteful number, since it uses less digits than its factorization.

642556800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 642556800 is about 25348.7041088889. The cubic root of 642556800 is about 862.9199467257.

The spelling of 642556800 in words is "six hundred forty-two million, five hundred fifty-six thousand, eight hundred".