165645647 has 4 divisors (see below), whose sum is σ = 165677496. Its totient is φ = 165613800.

The previous prime is 165645611. The next prime is 165645659. The reversal of 165645647 is 746546561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165645647 - 2¹² = 165641551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165645598 and 165645607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165645047) 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, 6104 + ... + 19197.

It is an arithmetic number, because the mean of its divisors is an integer number (41419374).

Almost surely, 2^165645647 is an apocalyptic number.

165645647 is a deficient number, since it is larger than the sum of its proper divisors (31849).

165645647 is an equidigital number, since it uses as much as digits as its factorization.

165645647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31848.

The product of its digits is 604800, while the sum is 44.

The square root of 165645647 is about 12870.3398168036. The cubic root of 165645647 is about 549.1951279560.

The spelling of 165645647 in words is "one hundred sixty-five million, six hundred forty-five thousand, six hundred forty-seven".