638315329 has 2 divisors, whose sum is σ = 638315330. Its totient is φ = 638315328.

The previous prime is 638315299. The next prime is 638315333. The reversal of 638315329 is 923513836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 591802929 + 46512400 = 24327^2 + 6820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638315329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 638315291 and 638315300.

It is not a weakly prime, because it can be changed into another prime (638315369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319157664 + 319157665.

It is an arithmetic number, because the mean of its divisors is an integer number (319157665).

Almost surely, 2^638315329 is an apocalyptic number.

It is an amenable number.

638315329 is a deficient number, since it is larger than the sum of its proper divisors (1).

638315329 is an equidigital number, since it uses as much as digits as its factorization.

638315329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 40.

The square root of 638315329 is about 25264.9031068793. The cubic root of 638315329 is about 861.0170628954.

It can be divided in two parts, 6383 and 15329, that added together give a palindrome (21712).

The spelling of 638315329 in words is "six hundred thirty-eight million, three hundred fifteen thousand, three hundred twenty-nine".