642444728180 has 12 divisors (see below), whose sum is σ = 1349133929220. Its totient is φ = 256977891264.

The previous prime is 642444728173. The next prime is 642444728183. The reversal of 642444728180 is 81827444246.

It can be written as a sum of positive squares in 2 ways, for example, as 372134160784 + 270310567396 = 610028^2 + 519914^2 .

It is a super-2 number, since 2×642444728180² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642444728183) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 16061118185 + ... + 16061118224.

It is an arithmetic number, because the mean of its divisors is an integer number (112427827435).

Almost surely, 2^642444728180 is an apocalyptic number.

It is an amenable number.

642444728180 is an abundant number, since it is smaller than the sum of its proper divisors (706689201040).

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

642444728180 is a wasteful number, since it uses less digits than its factorization.

642444728180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32122236418 (or 32122236416 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 50.

The spelling of 642444728180 in words is "six hundred forty-two billion, four hundred forty-four million, seven hundred twenty-eight thousand, one hundred eighty".