638353445357 has 2 divisors, whose sum is σ = 638353445358. Its totient is φ = 638353445356.

The previous prime is 638353445341. The next prime is 638353445413. The reversal of 638353445357 is 753544353836.

It is an a-pointer prime, because the next prime (638353445413) can be obtained adding 638353445357 to its sum of digits (56).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 577062045316 + 61291400041 = 759646^2 + 247571^2 .

It is a cyclic number.

It is not a de Polignac number, because 638353445357 - 2⁴ = 638353445341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638353405357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319176722678 + 319176722679.

It is an arithmetic number, because the mean of its divisors is an integer number (319176722679).

Almost surely, 2^638353445357 is an apocalyptic number.

It is an amenable number.

638353445357 is a deficient number, since it is larger than the sum of its proper divisors (1).

638353445357 is an equidigital number, since it uses as much as digits as its factorization.

638353445357 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432000, while the sum is 56.

The spelling of 638353445357 in words is "six hundred thirty-eight billion, three hundred fifty-three million, four hundred forty-five thousand, three hundred fifty-seven".