638842782655 has 128 divisors (see below), whose sum is σ = 1022019710976. Its totient is φ = 371119104000.

The previous prime is 638842782649. The next prime is 638842782667. The reversal of 638842782655 is 556287248836.

It is not a de Polignac number, because 638842782655 - 2¹¹ = 638842780607 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 368633169 + ... + 368634901.

It is an arithmetic number, because the mean of its divisors is an integer number (7984528992).

Almost surely, 2^638842782655 is an apocalyptic number.

638842782655 is a deficient number, since it is larger than the sum of its proper divisors (383176928321).

638842782655 is a wasteful number, since it uses less digits than its factorization.

638842782655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2297.

The product of its digits is 154828800, while the sum is 64.

The spelling of 638842782655 in words is "six hundred thirty-eight billion, eight hundred forty-two million, seven hundred eighty-two thousand, six hundred fifty-five".