638647333 has 2 divisors, whose sum is σ = 638647334. Its totient is φ = 638647332.

The previous prime is 638647301. The next prime is 638647393. The reversal of 638647333 is 333746836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 371063169 + 267584164 = 19263^2 + 16358^2 .

It is a cyclic number.

It is not a de Polignac number, because 638647333 - 2⁵ = 638647301 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638647333.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638647393) 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, 319323666 + 319323667.

It is an arithmetic number, because the mean of its divisors is an integer number (319323667).

Almost surely, 2^638647333 is an apocalyptic number.

It is an amenable number.

638647333 is a deficient number, since it is larger than the sum of its proper divisors (1).

638647333 is an equidigital number, since it uses as much as digits as its factorization.

638647333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 43.

The square root of 638647333 is about 25271.4727113400. The cubic root of 638647333 is about 861.1663159626.

The spelling of 638647333 in words is "six hundred thirty-eight million, six hundred forty-seven thousand, three hundred thirty-three".