1665385344 has 288 divisors, whose sum is σ = 5639928840. Its totient is φ = 470292480.

The previous prime is 1665385303. The next prime is 1665385363. The reversal of 1665385344 is 4435835661.

1665385344 is a `hidden beast` number, since 1 + 66 + 53 + 8 + 534 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a self number, because there is not a number n which added to its sum of digits gives 1665385344.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9200934 + ... + 9201114.

Almost surely, 2^1665385344 is an apocalyptic number.

1665385344 is a gapful number since it is divisible by the number (14) 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 1665385344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2819964420).

1665385344 is an abundant number, since it is smaller than the sum of its proper divisors (3974543496).

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

1665385344 is a wasteful number, since it uses less digits than its factorization.

1665385344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378 (or 356 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 1665385344 is about 40809.1330954236. The cubic root of 1665385344 is about 1185.3271884003.

The spelling of 1665385344 in words is "one billion, six hundred sixty-five million, three hundred eighty-five thousand, three hundred forty-four".