642756560 has 40 divisors (see below), whose sum is σ = 1495737600. Its totient is φ = 256874112.

The previous prime is 642756559. The next prime is 642756577. The reversal of 642756560 is 65657246.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109049 + ... + 114791.

It is an arithmetic number, because the mean of its divisors is an integer number (37393440).

Almost surely, 2^642756560 is an apocalyptic number.

It is an amenable number.

642756560 is an abundant number, since it is smaller than the sum of its proper divisors (852981040).

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

642756560 is a wasteful number, since it uses less digits than its factorization.

642756560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7155 (or 7149 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 41.

The square root of 642756560 is about 25352.6440435707. The cubic root of 642756560 is about 863.0093598477.

The spelling of 642756560 in words is "six hundred forty-two million, seven hundred fifty-six thousand, five hundred sixty".