165556549 has 4 divisors (see below), whose sum is σ = 165686080. Its totient is φ = 165427020.

The previous prime is 165556511. The next prime is 165556561. The reversal of 165556549 is 945655561.

165556549 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165556549 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165556499 and 165556508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165550549) 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, 62829 + ... + 65410.

It is an arithmetic number, because the mean of its divisors is an integer number (41421520).

Almost surely, 2^165556549 is an apocalyptic number.

It is an amenable number.

165556549 is a deficient number, since it is larger than the sum of its proper divisors (129531).

165556549 is a wasteful number, since it uses less digits than its factorization.

165556549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129530.

The product of its digits is 810000, while the sum is 46.

The square root of 165556549 is about 12866.8779818571. The cubic root of 165556549 is about 549.0966426969.

It can be divided in two parts, 16555 and 6549, that added together give a square (23104 = 152²).

The spelling of 165556549 in words is "one hundred sixty-five million, five hundred fifty-six thousand, five hundred forty-nine".