165641445 has 24 divisors (see below), whose sum is σ = 288785016. Its totient is φ = 87827328.

The previous prime is 165641429. The next prime is 165641459. The reversal of 165641445 is 544146561.

165641445 is a `hidden beast` number, since 1 + 6 + 5 + 641 + 4 + 4 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 12723489 + 152917956 = 3567^2 + 12366^2 .

It is not a de Polignac number, because 165641445 - 2⁴ = 165641429 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2854 + ... + 18423.

It is an arithmetic number, because the mean of its divisors is an integer number (12032709).

Almost surely, 2^165641445 is an apocalyptic number.

165641445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165641445 is a deficient number, since it is larger than the sum of its proper divisors (123143571).

165641445 is a wasteful number, since it uses less digits than its factorization.

165641445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21461 (or 21458 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 165641445 is about 12870.1765722153. The cubic root of 165641445 is about 549.1904840319.

The spelling of 165641445 in words is "one hundred sixty-five million, six hundred forty-one thousand, four hundred forty-five".