638282849 has 2 divisors, whose sum is σ = 638282850. Its totient is φ = 638282848.

The previous prime is 638282809. The next prime is 638282891. The reversal of 638282849 is 948282836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 635392849 + 2890000 = 25207^2 + 1700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638282849 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638282797 and 638282806.

It is not a weakly prime, because it can be changed into another prime (638282809) 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, 319141424 + 319141425.

It is an arithmetic number, because the mean of its divisors is an integer number (319141425).

Almost surely, 2^638282849 is an apocalyptic number.

It is an amenable number.

638282849 is a deficient number, since it is larger than the sum of its proper divisors (1).

638282849 is an equidigital number, since it uses as much as digits as its factorization.

638282849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1327104, while the sum is 50.

The square root of 638282849 is about 25264.2603097736. The cubic root of 638282849 is about 861.0024586670.

The spelling of 638282849 in words is "six hundred thirty-eight million, two hundred eighty-two thousand, eight hundred forty-nine".