164564789 has 4 divisors (see below), whose sum is σ = 169012524. Its totient is φ = 160117056.

The previous prime is 164564779. The next prime is 164564801. The reversal of 164564789 is 987465461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 987465461 = 317 ⋅3115033.

It can be written as a sum of positive squares in 2 ways, for example, as 120780100 + 43784689 = 10990^2 + 6617^2 .

It is not a de Polignac number, because 164564789 - 2¹⁶ = 164499253 is a prime.

It is a super-2 number, since 2×164564789² = 54163139557229042, 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 (164564749) 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, 2223812 + ... + 2223885.

It is an arithmetic number, because the mean of its divisors is an integer number (42253131).

Almost surely, 2^164564789 is an apocalyptic number.

It is an amenable number.

164564789 is a deficient number, since it is larger than the sum of its proper divisors (4447735).

164564789 is an equidigital number, since it uses as much as digits as its factorization.

164564789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4447734.

The product of its digits is 1451520, while the sum is 50.

The square root of 164564789 is about 12828.2808279208. The cubic root of 164564789 is about 547.9979986873.

The spelling of 164564789 in words is "one hundred sixty-four million, five hundred sixty-four thousand, seven hundred eighty-nine".