1644056660 has 12 divisors (see below), whose sum is σ = 3452519028. Its totient is φ = 657622656.

The previous prime is 1644056657. The next prime is 1644056699. The reversal of 1644056660 is 666504461.

1644056660 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 405861316 + 1238195344 = 20146^2 + 35188^2 .

It is a super-3 number, since 3×1644056660³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41101397 + ... + 41101436.

It is an arithmetic number, because the mean of its divisors is an integer number (287709919).

Almost surely, 2^1644056660 is an apocalyptic number.

1644056660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644056660 is an abundant number, since it is smaller than the sum of its proper divisors (1808462368).

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

1644056660 is a wasteful number, since it uses less digits than its factorization.

1644056660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82202842 (or 82202840 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 1644056660 is about 40546.9685673294. The cubic root of 1644056660 is about 1180.2452473110.

The spelling of 1644056660 in words is "one billion, six hundred forty-four million, fifty-six thousand, six hundred sixty".