165561667 has 8 divisors (see below), whose sum is σ = 172045440. Its totient is φ = 159129600.

The previous prime is 165561661. The next prime is 165561679. The reversal of 165561667 is 766165561.

165561667 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165561667 - 2¹¹ = 165559619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165561661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6334 + ... + 19267.

It is an arithmetic number, because the mean of its divisors is an integer number (21505680).

Almost surely, 2^165561667 is an apocalyptic number.

165561667 is a deficient number, since it is larger than the sum of its proper divisors (6483773).

165561667 is a wasteful number, since it uses less digits than its factorization.

165561667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25853.

The product of its digits is 226800, while the sum is 43.

The square root of 165561667 is about 12867.0768630641. The cubic root of 165561667 is about 549.1023008797.

The spelling of 165561667 in words is "one hundred sixty-five million, five hundred sixty-one thousand, six hundred sixty-seven".