638372775845 has 16 divisors (see below), whose sum is σ = 875498087808. Its totient is φ = 437733620160.

The previous prime is 638372775811. The next prime is 638372775877. The reversal of 638372775845 is 548577273836.

It is not a de Polignac number, because 638372775845 - 2⁸ = 638372775589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2453450 + ... + 2701140.

It is an arithmetic number, because the mean of its divisors is an integer number (54718630488).

Almost surely, 2^638372775845 is an apocalyptic number.

It is an amenable number.

638372775845 is a deficient number, since it is larger than the sum of its proper divisors (237125311963).

638372775845 is a wasteful number, since it uses less digits than its factorization.

638372775845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321340.

The product of its digits is 237081600, while the sum is 65.

The spelling of 638372775845 in words is "six hundred thirty-eight billion, three hundred seventy-two million, seven hundred seventy-five thousand, eight hundred forty-five".