164531021 has 2 divisors, whose sum is σ = 164531022. Its totient is φ = 164531020.

The previous prime is 164530997. The next prime is 164531041. The reversal of 164531021 is 120135461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 146773225 + 17757796 = 12115^2 + 4214^2 .

It is a cyclic number.

It is not a de Polignac number, because 164531021 - 2⁶ = 164530957 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 (164531041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82265510 + 82265511.

It is an arithmetic number, because the mean of its divisors is an integer number (82265511).

Almost surely, 2^164531021 is an apocalyptic number.

It is an amenable number.

164531021 is a deficient number, since it is larger than the sum of its proper divisors (1).

164531021 is an equidigital number, since it uses as much as digits as its factorization.

164531021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 164531021 is about 12826.9646058606. The cubic root of 164531021 is about 547.9605138313.

Adding to 164531021 its reverse (120135461), we get a palindrome (284666482).

The spelling of 164531021 in words is "one hundred sixty-four million, five hundred thirty-one thousand, twenty-one".