1665872000 has 128 divisors (see below), whose sum is σ = 4460929200. Its totient is φ = 615014400.

The previous prime is 1665871993. The next prime is 1665872003. The reversal of 1665872000 is 2785661.

It can be written as a sum of positive squares in 8 ways, for example, as 5798464 + 1660073536 = 2408^2 + 40744^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (1665872003) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 203996 + ... + 212004.

Almost surely, 2^1665872000 is an apocalyptic number.

1665872000 is a gapful number since it is divisible by the number (10) 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 1665872000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2230464600).

1665872000 is an abundant number, since it is smaller than the sum of its proper divisors (2795057200).

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

1665872000 is an equidigital number, since it uses as much as digits as its factorization.

1665872000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8051 (or 8029 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 1665872000 is about 40815.0952467344. The cubic root of 1665872000 is about 1185.4426352369.

The spelling of 1665872000 in words is "one billion, six hundred sixty-five million, eight hundred seventy-two thousand".