638283817 has 2 divisors, whose sum is σ = 638283818. Its totient is φ = 638283816.

The previous prime is 638283761. The next prime is 638283827. The reversal of 638283817 is 718382836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 448422976 + 189860841 = 21176^2 + 13779^2 .

It is a cyclic number.

It is not a de Polignac number, because 638283817 - 2¹⁵ = 638251049 is a prime.

It is not a weakly prime, because it can be changed into another prime (638283827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319141908 + 319141909.

It is an arithmetic number, because the mean of its divisors is an integer number (319141909).

Almost surely, 2^638283817 is an apocalyptic number.

It is an amenable number.

638283817 is a deficient number, since it is larger than the sum of its proper divisors (1).

638283817 is an equidigital number, since it uses as much as digits as its factorization.

638283817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 46.

The square root of 638283817 is about 25264.2794672637. The cubic root of 638283817 is about 861.0028939233.

The spelling of 638283817 in words is "six hundred thirty-eight million, two hundred eighty-three thousand, eight hundred seventeen".