164644430081 has 2 divisors, whose sum is σ = 164644430082. Its totient is φ = 164644430080.

The previous prime is 164644430077. The next prime is 164644430101. The reversal of 164644430081 is 180034446461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163572522481 + 1071907600 = 404441^2 + 32740^2 .

It is a cyclic number.

It is not a de Polignac number, because 164644430081 - 2² = 164644430077 is a prime.

It is a super-2 number, since 2×164644430081² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (164644430021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82322215040 + 82322215041.

It is an arithmetic number, because the mean of its divisors is an integer number (82322215041).

Almost surely, 2^164644430081 is an apocalyptic number.

It is an amenable number.

164644430081 is a deficient number, since it is larger than the sum of its proper divisors (1).

164644430081 is an equidigital number, since it uses as much as digits as its factorization.

164644430081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 221184, while the sum is 41.

The spelling of 164644430081 in words is "one hundred sixty-four billion, six hundred forty-four million, four hundred thirty thousand, eighty-one".