165680553 has 4 divisors (see below), whose sum is σ = 220907408. Its totient is φ = 110453700.

The previous prime is 165680519. The next prime is 165680563. The reversal of 165680553 is 355086561.

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.

It is not a de Polignac number, because 165680553 - 2⁹ = 165680041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165680563) 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, 27613423 + ... + 27613428.

It is an arithmetic number, because the mean of its divisors is an integer number (55226852).

Almost surely, 2^165680553 is an apocalyptic number.

It is an amenable number.

165680553 is a deficient number, since it is larger than the sum of its proper divisors (55226855).

165680553 is an equidigital number, since it uses as much as digits as its factorization.

165680553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55226854.

The product of its (nonzero) digits is 108000, while the sum is 39.

The square root of 165680553 is about 12871.6958090222. The cubic root of 165680553 is about 549.2337019825.

The spelling of 165680553 in words is "one hundred sixty-five million, six hundred eighty thousand, five hundred fifty-three".