164881021 has 2 divisors, whose sum is σ = 164881022. Its totient is φ = 164881020.

The previous prime is 164881009. The next prime is 164881027. The reversal of 164881021 is 120188461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163558521 + 1322500 = 12789^2 + 1150^2 .

It is a cyclic number.

It is not a de Polignac number, because 164881021 - 2¹⁵ = 164848253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164881027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82440510 + 82440511.

It is an arithmetic number, because the mean of its divisors is an integer number (82440511).

Almost surely, 2^164881021 is an apocalyptic number.

It is an amenable number.

164881021 is a deficient number, since it is larger than the sum of its proper divisors (1).

164881021 is an equidigital number, since it uses as much as digits as its factorization.

164881021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 164881021 is about 12840.6004921888. The cubic root of 164881021 is about 548.3487898461.

The spelling of 164881021 in words is "one hundred sixty-four million, eight hundred eighty-one thousand, twenty-one".