164128721789 has 2 divisors, whose sum is σ = 164128721790. Its totient is φ = 164128721788.

The previous prime is 164128721777. The next prime is 164128721791. The reversal of 164128721789 is 987127821461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136611552100 + 27517169689 = 369610^2 + 165883^2 .

It is an emirp because it is prime and its reverse (987127821461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 164128721789 - 2⁴ = 164128721773 is a prime.

Together with 164128721791, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164128721759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82064360894 + 82064360895.

It is an arithmetic number, because the mean of its divisors is an integer number (82064360895).

Almost surely, 2^164128721789 is an apocalyptic number.

It is an amenable number.

164128721789 is a deficient number, since it is larger than the sum of its proper divisors (1).

164128721789 is an equidigital number, since it uses as much as digits as its factorization.

164128721789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2709504, while the sum is 56.

The spelling of 164128721789 in words is "one hundred sixty-four billion, one hundred twenty-eight million, seven hundred twenty-one thousand, seven hundred eighty-nine".