165680641 has 4 divisors (see below), whose sum is σ = 189349312. Its totient is φ = 142011972.

The previous prime is 165680629. The next prime is 165680651. The reversal of 165680641 is 146086561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 146086561 = 281 ⋅519881.

It is a cyclic number.

It is not a de Polignac number, because 165680641 - 2¹¹ = 165678593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165680641.

It is not an unprimeable number, because it can be changed into a prime (165680611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11834325 + ... + 11834338.

It is an arithmetic number, because the mean of its divisors is an integer number (47337328).

Almost surely, 2^165680641 is an apocalyptic number.

It is an amenable number.

165680641 is a deficient number, since it is larger than the sum of its proper divisors (23668671).

165680641 is an equidigital number, since it uses as much as digits as its factorization.

165680641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23668670.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 165680641 is about 12871.6992273748. The cubic root of 165680641 is about 549.2337992229.

The spelling of 165680641 in words is "one hundred sixty-five million, six hundred eighty thousand, six hundred forty-one".