164189581 has 4 divisors (see below), whose sum is σ = 164279392. Its totient is φ = 164099772.

The previous prime is 164189569. The next prime is 164189591. The reversal of 164189581 is 185981461.

164189581 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 not a de Polignac number, because 164189581 - 2¹¹ = 164187533 is a prime.

It is a super-2 number, since 2×164189581² = 53916437017911122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164189551) 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, 42105 + ... + 45838.

It is an arithmetic number, because the mean of its divisors is an integer number (41069848).

Almost surely, 2^164189581 is an apocalyptic number.

It is an amenable number.

164189581 is a deficient number, since it is larger than the sum of its proper divisors (89811).

164189581 is an equidigital number, since it uses as much as digits as its factorization.

164189581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89810.

The product of its digits is 69120, while the sum is 43.

The square root of 164189581 is about 12813.6482314757. The cubic root of 164189581 is about 547.5812029707.

The spelling of 164189581 in words is "one hundred sixty-four million, one hundred eighty-nine thousand, five hundred eighty-one".