165744640 has 52 divisors (see below), whose sum is σ = 397787724. Its totient is φ = 66289664.

The previous prime is 165744589. The next prime is 165744641. The reversal of 165744640 is 46447561.

It can be written as a sum of positive squares in 2 ways, for example, as 66064384 + 99680256 = 8128^2 + 9984^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 165744640.

It is not an unprimeable number, because it can be changed into a prime (165744641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16434 + ... + 24526.

Almost surely, 2^165744640 is an apocalyptic number.

165744640 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 165744640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198893862).

165744640 is an abundant number, since it is smaller than the sum of its proper divisors (232043084).

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

165744640 is an frugal number, since it uses more digits than its factorization.

165744640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8122 (or 8100 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 165744640 is about 12874.1850227500. The cubic root of 165744640 is about 549.3045093327.

The spelling of 165744640 in words is "one hundred sixty-five million, seven hundred forty-four thousand, six hundred forty".