638887467767 has 4 divisors (see below), whose sum is σ = 676469083536. Its totient is φ = 601305852000.

The previous prime is 638887467731. The next prime is 638887467787. The reversal of 638887467767 is 767764788836.

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 638887467767 - 2¹² = 638887463671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638887467707) 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, 18790807859 + ... + 18790807892.

It is an arithmetic number, because the mean of its divisors is an integer number (169117270884).

Almost surely, 2^638887467767 is an apocalyptic number.

638887467767 is a deficient number, since it is larger than the sum of its proper divisors (37581615769).

638887467767 is a wasteful number, since it uses less digits than its factorization.

638887467767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37581615768.

The product of its digits is 3186376704, while the sum is 77.

The spelling of 638887467767 in words is "six hundred thirty-eight billion, eight hundred eighty-seven million, four hundred sixty-seven thousand, seven hundred sixty-seven".