638221402543265 has 16 divisors (see below), whose sum is σ = 790625593981440. Its totient is φ = 494072788344960.

The previous prime is 638221402543247. The next prime is 638221402543271. The reversal of 638221402543265 is 562345204122836.

It is not a de Polignac number, because 638221402543265 - 2²⁶ = 638221335434401 is a prime.

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, 139846739 + ... + 144338328.

It is an arithmetic number, because the mean of its divisors is an integer number (49414099623840).

Almost surely, 2^{638221402543265} is an apocalyptic number.

It is an amenable number.

638221402543265 is a deficient number, since it is larger than the sum of its proper divisors (152404191438175).

638221402543265 is a wasteful number, since it uses less digits than its factorization.

638221402543265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284199592.

The product of its (nonzero) digits is 16588800, while the sum is 53.

The spelling of 638221402543265 in words is "six hundred thirty-eight trillion, two hundred twenty-one billion, four hundred two million, five hundred forty-three thousand, two hundred sixty-five".