638205009121 has 8 divisors (see below), whose sum is σ = 640246892544. Its totient is φ = 636163306320.

The previous prime is 638205009119. The next prime is 638205009157. The reversal of 638205009121 is 121900502836.

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 638205009121 - 2¹ = 638205009119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638205049121) 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, 13166496 + ... + 13214878.

It is an arithmetic number, because the mean of its divisors is an integer number (80030861568).

Almost surely, 2^638205009121 is an apocalyptic number.

It is an amenable number.

638205009121 is a deficient number, since it is larger than the sum of its proper divisors (2041883423).

638205009121 is a wasteful number, since it uses less digits than its factorization.

638205009121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90311.

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 638205009121 in words is "six hundred thirty-eight billion, two hundred five million, nine thousand, one hundred twenty-one".