165666543 has 8 divisors (see below), whose sum is σ = 252444288. Its totient is φ = 94666584.

The previous prime is 165666541. The next prime is 165666551. The reversal of 165666543 is 345666561.

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

It is not a de Polignac number, because 165666543 - 2¹ = 165666541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165666495 and 165666504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165666541) 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, 3944421 + ... + 3944462.

It is an arithmetic number, because the mean of its divisors is an integer number (31555536).

Almost surely, 2^165666543 is an apocalyptic number.

165666543 is a deficient number, since it is larger than the sum of its proper divisors (86777745).

165666543 is an equidigital number, since it uses as much as digits as its factorization.

165666543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7888893.

The product of its digits is 388800, while the sum is 42.

The square root of 165666543 is about 12871.1515801812. The cubic root of 165666543 is about 549.2182204209.

The spelling of 165666543 in words is "one hundred sixty-five million, six hundred sixty-six thousand, five hundred forty-three".