165539566 has 16 divisors (see below), whose sum is σ = 258203520. Its totient is φ = 79511040.

The previous prime is 165539531. The next prime is 165539573. The reversal of 165539566 is 665935561.

It is a super-2 number, since 2×165539566² = 54806695822936712, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1251 + ... + 18238.

It is an arithmetic number, because the mean of its divisors is an integer number (16137720).

Almost surely, 2^165539566 is an apocalyptic number.

165539566 is a deficient number, since it is larger than the sum of its proper divisors (92663954).

165539566 is a wasteful number, since it uses less digits than its factorization.

165539566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19659.

The product of its digits is 729000, while the sum is 46.

The square root of 165539566 is about 12866.2180146304. The cubic root of 165539566 is about 549.0778663790.

The spelling of 165539566 in words is "one hundred sixty-five million, five hundred thirty-nine thousand, five hundred sixty-six".