638844676406 has 8 divisors (see below), whose sum is σ = 967058455440. Its totient is φ = 316491857928.

The previous prime is 638844676307. The next prime is 638844676409. The reversal of 638844676406 is 604676448836.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638844676409) 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, 1465239866 + ... + 1465240301.

It is an arithmetic number, because the mean of its divisors is an integer number (120882306930).

Almost surely, 2^638844676406 is an apocalyptic number.

638844676406 is a deficient number, since it is larger than the sum of its proper divisors (328213779034).

638844676406 is a wasteful number, since it uses less digits than its factorization.

638844676406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2930480278.

The product of its (nonzero) digits is 111476736, while the sum is 62.

The spelling of 638844676406 in words is "six hundred thirty-eight billion, eight hundred forty-four million, six hundred seventy-six thousand, four hundred six".