642871680 has 256 divisors, whose sum is σ = 2276640000. Its totient is φ = 152985600.

The previous prime is 642871667. The next prime is 642871693. The reversal of 642871680 is 86178246.

It is an interprime number because it is at equal distance from previous prime (642871667) and next prime (642871693).

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 31 ways as a sum of consecutive naturals, for example, 1288071 + ... + 1288569.

It is an arithmetic number, because the mean of its divisors is an integer number (8893125).

Almost surely, 2^642871680 is an apocalyptic number.

642871680 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 642871680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1138320000).

642871680 is an abundant number, since it is smaller than the sum of its proper divisors (1633768320).

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

642871680 is a wasteful number, since it uses less digits than its factorization.

642871680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593 (or 581 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 642871680 is about 25354.9143165580. The cubic root of 642871680 is about 863.0608794602.

The spelling of 642871680 in words is "six hundred forty-two million, eight hundred seventy-one thousand, six hundred eighty".