646228873 has 2 divisors, whose sum is σ = 646228874. Its totient is φ = 646228872.

The previous prime is 646228831. The next prime is 646228879. The reversal of 646228873 is 378822646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 548871184 + 97357689 = 23428^2 + 9867^2 .

It is a cyclic number.

It is not a de Polignac number, because 646228873 - 2²⁹ = 109357961 is a prime.

It is a super-2 number, since 2×646228873² = 835223512597700258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (646228879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323114436 + 323114437.

It is an arithmetic number, because the mean of its divisors is an integer number (323114437).

Almost surely, 2^646228873 is an apocalyptic number.

It is an amenable number.

646228873 is a deficient number, since it is larger than the sum of its proper divisors (1).

646228873 is an equidigital number, since it uses as much as digits as its factorization.

646228873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 774144, while the sum is 46.

The square root of 646228873 is about 25421.0320994251. The cubic root of 646228873 is about 864.5606255339.

The spelling of 646228873 in words is "six hundred forty-six million, two hundred twenty-eight thousand, eight hundred seventy-three".