642759660 has 36 divisors (see below), whose sum is σ = 1949704848. Its totient is φ = 171402528.

The previous prime is 642759659. The next prime is 642759701. The reversal of 642759660 is 66957246.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1785264 + ... + 1785623.

It is an arithmetic number, because the mean of its divisors is an integer number (54158468).

Almost surely, 2^642759660 is an apocalyptic number.

642759660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642759660 is an abundant number, since it is smaller than the sum of its proper divisors (1306945188).

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

642759660 is a wasteful number, since it uses less digits than its factorization.

642759660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3570902 (or 3570897 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 642759660 is about 25352.7051811044. The cubic root of 642759660 is about 863.0107472702.

The spelling of 642759660 in words is "six hundred forty-two million, seven hundred fifty-nine thousand, six hundred sixty".