1665589944 has 64 divisors (see below), whose sum is σ = 4336740000. Its totient is φ = 532421120.

The previous prime is 1665589931. The next prime is 1665589949. The reversal of 1665589944 is 4499855661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665589949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95674 + ... + 111734.

Almost surely, 2^1665589944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665589944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2168370000).

1665589944 is an abundant number, since it is smaller than the sum of its proper divisors (2671150056).

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

1665589944 is a wasteful number, since it uses less digits than its factorization.

1665589944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16248 (or 16244 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 57.

The square root of 1665589944 is about 40811.6398102306. The cubic root of 1665589944 is about 1185.3757273191.

The spelling of 1665589944 in words is "one billion, six hundred sixty-five million, five hundred eighty-nine thousand, nine hundred forty-four".