646752173 has 2 divisors, whose sum is σ = 646752174. Its totient is φ = 646752172.

The previous prime is 646752151. The next prime is 646752181. The reversal of 646752173 is 371257646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634939204 + 11812969 = 25198^2 + 3437^2 .

It is a cyclic number.

It is not a de Polignac number, because 646752173 - 2¹⁶ = 646686637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646752173.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646752373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323376086 + 323376087.

It is an arithmetic number, because the mean of its divisors is an integer number (323376087).

Almost surely, 2^646752173 is an apocalyptic number.

It is an amenable number.

646752173 is a deficient number, since it is larger than the sum of its proper divisors (1).

646752173 is an equidigital number, since it uses as much as digits as its factorization.

646752173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 41.

The square root of 646752173 is about 25431.3226750006. The cubic root of 646752173 is about 864.7939291040.

The spelling of 646752173 in words is "six hundred forty-six million, seven hundred fifty-two thousand, one hundred seventy-three".