164383721 has 2 divisors, whose sum is σ = 164383722. Its totient is φ = 164383720.

The previous prime is 164383651. The next prime is 164383733. The reversal of 164383721 is 127383461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160909225 + 3474496 = 12685^2 + 1864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164383721 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (164383771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82191860 + 82191861.

It is an arithmetic number, because the mean of its divisors is an integer number (82191861).

Almost surely, 2^164383721 is an apocalyptic number.

It is an amenable number.

164383721 is a deficient number, since it is larger than the sum of its proper divisors (1).

164383721 is an equidigital number, since it uses as much as digits as its factorization.

164383721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 35.

The square root of 164383721 is about 12821.2215096690. The cubic root of 164383721 is about 547.7969404570.

The spelling of 164383721 in words is "one hundred sixty-four million, three hundred eighty-three thousand, seven hundred twenty-one".