165791440 has 20 divisors (see below), whose sum is σ = 385465284. Its totient is φ = 66316544.

The previous prime is 165791401. The next prime is 165791447. The reversal of 165791440 is 44197561.

It can be written as a sum of positive squares in 2 ways, for example, as 59783824 + 106007616 = 7732^2 + 10296^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 165791440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165791447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1036117 + ... + 1036276.

Almost surely, 2^165791440 is an apocalyptic number.

165791440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165791440 is an abundant number, since it is smaller than the sum of its proper divisors (219673844).

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

165791440 is a wasteful number, since it uses less digits than its factorization.

165791440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2072406 (or 2072400 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 165791440 is about 12876.0024852436. The cubic root of 165791440 is about 549.3562053872.

The spelling of 165791440 in words is "one hundred sixty-five million, seven hundred ninety-one thousand, four hundred forty".