164026561 has 2 divisors, whose sum is σ = 164026562. Its totient is φ = 164026560.

The previous prime is 164026559. The next prime is 164026589. The reversal of 164026561 is 165620461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162715536 + 1311025 = 12756^2 + 1145^2 .

It is a cyclic number.

It is not a de Polignac number, because 164026561 - 2¹ = 164026559 is a prime.

Together with 164026559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (164026861) 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, 82013280 + 82013281.

It is an arithmetic number, because the mean of its divisors is an integer number (82013281).

Almost surely, 2^164026561 is an apocalyptic number.

It is an amenable number.

164026561 is a deficient number, since it is larger than the sum of its proper divisors (1).

164026561 is an equidigital number, since it uses as much as digits as its factorization.

164026561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 164026561 is about 12807.2854657027. The cubic root of 164026561 is about 547.3999160967.

The spelling of 164026561 in words is "one hundred sixty-four million, twenty-six thousand, five hundred sixty-one".