165481581 has 8 divisors (see below), whose sum is σ = 220914144. Its totient is φ = 110185040.

The previous prime is 165481579. The next prime is 165481597. The reversal of 165481581 is 185184561.

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

It is a cyclic number.

It is not a de Polignac number, because 165481581 - 2¹ = 165481579 is a prime.

It is a super-2 number, since 2×165481581² = 54768307300519122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165481571) 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, 31131 + ... + 36056.

It is an arithmetic number, because the mean of its divisors is an integer number (27614268).

Almost surely, 2^165481581 is an apocalyptic number.

It is an amenable number.

165481581 is a deficient number, since it is larger than the sum of its proper divisors (55432563).

165481581 is an equidigital number, since it uses as much as digits as its factorization.

165481581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68011.

The product of its digits is 38400, while the sum is 39.

The square root of 165481581 is about 12863.9644355852. The cubic root of 165481581 is about 549.0137487806.

The spelling of 165481581 in words is "one hundred sixty-five million, four hundred eighty-one thousand, five hundred eighty-one".