164671921 has 2 divisors, whose sum is σ = 164671922. Its totient is φ = 164671920.

The previous prime is 164671919. The next prime is 164671937. The reversal of 164671921 is 129176461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161290000 + 3381921 = 12700^2 + 1839^2 .

It is a cyclic number.

It is not a de Polignac number, because 164671921 - 2¹ = 164671919 is a prime.

Together with 164671919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (164671961) 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, 82335960 + 82335961.

It is an arithmetic number, because the mean of its divisors is an integer number (82335961).

Almost surely, 2^164671921 is an apocalyptic number.

It is an amenable number.

164671921 is a deficient number, since it is larger than the sum of its proper divisors (1).

164671921 is an equidigital number, since it uses as much as digits as its factorization.

164671921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 37.

The square root of 164671921 is about 12832.4557665320. The cubic root of 164671921 is about 548.1168888154.

The spelling of 164671921 in words is "one hundred sixty-four million, six hundred seventy-one thousand, nine hundred twenty-one".