638396478267 has 8 divisors (see below), whose sum is σ = 851207937360. Its totient is φ = 425591335680.

The previous prime is 638396478259. The next prime is 638396478337. The reversal of 638396478267 is 762874693836.

638396478267 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638396478267 - 2³ = 638396478259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638396470267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1338042 + ... + 1751327.

It is an arithmetic number, because the mean of its divisors is an integer number (106400992170).

Almost surely, 2^638396478267 is an apocalyptic number.

638396478267 is a deficient number, since it is larger than the sum of its proper divisors (212811459093).

638396478267 is a wasteful number, since it uses less digits than its factorization.

638396478267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3158253.

The product of its digits is 438939648, while the sum is 69.

The spelling of 638396478267 in words is "six hundred thirty-eight billion, three hundred ninety-six million, four hundred seventy-eight thousand, two hundred sixty-seven".