165641181 has 4 divisors (see below), whose sum is σ = 220854912. Its totient is φ = 110427452.

The previous prime is 165641173. The next prime is 165641197. The reversal of 165641181 is 181146561.

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 not a de Polignac number, because 165641181 - 2³ = 165641173 is a prime.

It is a super-2 number, since 2×165641181² = 54874001686149522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165641171) 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, 27606861 + ... + 27606866.

It is an arithmetic number, because the mean of its divisors is an integer number (55213728).

Almost surely, 2^165641181 is an apocalyptic number.

It is an amenable number.

165641181 is a deficient number, since it is larger than the sum of its proper divisors (55213731).

165641181 is an equidigital number, since it uses as much as digits as its factorization.

165641181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55213730.

The product of its digits is 5760, while the sum is 33.

The square root of 165641181 is about 12870.1663159417. The cubic root of 165641181 is about 549.1901922644.

The spelling of 165641181 in words is "one hundred sixty-five million, six hundred forty-one thousand, one hundred eighty-one".