646023173 has 2 divisors, whose sum is σ = 646023174. Its totient is φ = 646023172.

The previous prime is 646023163. The next prime is 646023193. The reversal of 646023173 is 371320646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 592338244 + 53684929 = 24338^2 + 7327^2 .

It is a cyclic number.

It is not a de Polignac number, because 646023173 - 2¹⁰ = 646022149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646023163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323011586 + 323011587.

It is an arithmetic number, because the mean of its divisors is an integer number (323011587).

Almost surely, 2^646023173 is an apocalyptic number.

It is an amenable number.

646023173 is a deficient number, since it is larger than the sum of its proper divisors (1).

646023173 is an equidigital number, since it uses as much as digits as its factorization.

646023173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 646023173 is about 25416.9859149349. The cubic root of 646023173 is about 864.4688835310.

The spelling of 646023173 in words is "six hundred forty-six million, twenty-three thousand, one hundred seventy-three".