164421689 has 2 divisors, whose sum is σ = 164421690. Its totient is φ = 164421688.

The previous prime is 164421683. The next prime is 164421701. The reversal of 164421689 is 986124461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158256400 + 6165289 = 12580^2 + 2483^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164421689 is a prime.

It is a super-3 number, since 3×164421689³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (164421683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82210844 + 82210845.

It is an arithmetic number, because the mean of its divisors is an integer number (82210845).

Almost surely, 2^164421689 is an apocalyptic number.

It is an amenable number.

164421689 is a deficient number, since it is larger than the sum of its proper divisors (1).

164421689 is an equidigital number, since it uses as much as digits as its factorization.

164421689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 41.

The square root of 164421689 is about 12822.7020943325. The cubic root of 164421689 is about 547.8391124211.

The spelling of 164421689 in words is "one hundred sixty-four million, four hundred twenty-one thousand, six hundred eighty-nine".