638475425293 has 2 divisors, whose sum is σ = 638475425294. Its totient is φ = 638475425292.

The previous prime is 638475425267. The next prime is 638475425321. The reversal of 638475425293 is 392524574836.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 421768416969 + 216707008324 = 649437^2 + 465518^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638475425293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638475428293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319237712646 + 319237712647.

It is an arithmetic number, because the mean of its divisors is an integer number (319237712647).

Almost surely, 2^638475425293 is an apocalyptic number.

It is an amenable number.

638475425293 is a deficient number, since it is larger than the sum of its proper divisors (1).

638475425293 is an equidigital number, since it uses as much as digits as its factorization.

638475425293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43545600, while the sum is 58.

The spelling of 638475425293 in words is "six hundred thirty-eight billion, four hundred seventy-five million, four hundred twenty-five thousand, two hundred ninety-three".