164365261 has 2 divisors, whose sum is σ = 164365262. Its totient is φ = 164365260.

The previous prime is 164365259. The next prime is 164365273. The reversal of 164365261 is 162563461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158634025 + 5731236 = 12595^2 + 2394^2 .

It is an emirp because it is prime and its reverse (162563461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 164365261 - 2¹ = 164365259 is a prime.

Together with 164365259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164365361) 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, 82182630 + 82182631.

It is an arithmetic number, because the mean of its divisors is an integer number (82182631).

Almost surely, 2^164365261 is an apocalyptic number.

It is an amenable number.

164365261 is a deficient number, since it is larger than the sum of its proper divisors (1).

164365261 is an equidigital number, since it uses as much as digits as its factorization.

164365261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 34.

The square root of 164365261 is about 12820.5015892515. The cubic root of 164365261 is about 547.7764341481.

The spelling of 164365261 in words is "one hundred sixty-four million, three hundred sixty-five thousand, two hundred sixty-one".