638840771567 has 8 divisors (see below), whose sum is σ = 660935751840. Its totient is φ = 616750190560.

The previous prime is 638840771551. The next prime is 638840771573. The reversal of 638840771567 is 765177048836.

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

It is a cyclic number.

It is not a de Polignac number, because 638840771567 - 2⁴ = 638840771551 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 (638840771867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 803003 + ... + 1386540.

It is an arithmetic number, because the mean of its divisors is an integer number (82616968980).

Almost surely, 2^638840771567 is an apocalyptic number.

638840771567 is a deficient number, since it is larger than the sum of its proper divisors (22094980273).

638840771567 is a wasteful number, since it uses less digits than its factorization.

638840771567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2199633.

The product of its (nonzero) digits is 47416320, while the sum is 62.

The spelling of 638840771567 in words is "six hundred thirty-eight billion, eight hundred forty million, seven hundred seventy-one thousand, five hundred sixty-seven".