642682656 has 288 divisors, whose sum is σ = 2315634048. Its totient is φ = 164229120.

The previous prime is 642682643. The next prime is 642682679. The reversal of 642682656 is 656286246.

It is a tau number, because it is divible by the number of its divisors (288).

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 47 ways as a sum of consecutive naturals, for example, 1618650 + ... + 1619046.

It is an arithmetic number, because the mean of its divisors is an integer number (8040396).

Almost surely, 2^642682656 is an apocalyptic number.

642682656 is a gapful number since it is divisible by the number (66) 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 642682656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1157817024).

642682656 is an abundant number, since it is smaller than the sum of its proper divisors (1672951392).

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

642682656 is a wasteful number, since it uses less digits than its factorization.

642682656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504 (or 493 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The square root of 642682656 is about 25351.1864811097. The cubic root of 642682656 is about 862.9762823746.

The spelling of 642682656 in words is "six hundred forty-two million, six hundred eighty-two thousand, six hundred fifty-six".