638476540747 has 4 divisors (see below), whose sum is σ = 639302513760. Its totient is φ = 637650567736.

The previous prime is 638476540739. The next prime is 638476540783. The reversal of 638476540747 is 747045674836.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638476540747 - 2³ = 638476540739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638416540747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412985347 + ... + 412986892.

It is an arithmetic number, because the mean of its divisors is an integer number (159825628440).

Almost surely, 2^638476540747 is an apocalyptic number.

638476540747 is a deficient number, since it is larger than the sum of its proper divisors (825973013).

638476540747 is an equidigital number, since it uses as much as digits as its factorization.

638476540747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825973012.

The product of its (nonzero) digits is 94832640, while the sum is 61.

The spelling of 638476540747 in words is "six hundred thirty-eight billion, four hundred seventy-six million, five hundred forty thousand, seven hundred forty-seven".