638844847407 has 48 divisors (see below), whose sum is σ = 1052714426400. Its totient is φ = 369834080256.

The previous prime is 638844847397. The next prime is 638844847423. The reversal of 638844847407 is 704748448836.

638844847407 is a `hidden beast` number, since 6 + 3 + 8 + 84 + 484 + 74 + 0 + 7 = 666.

It is not a de Polignac number, because 638844847407 - 2⁴ = 638844847391 is a prime.

It is a super-2 number, since 2×638844847407² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638844847447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4175344 + ... + 4325642.

It is an arithmetic number, because the mean of its divisors is an integer number (21931550550).

Almost surely, 2^638844847407 is an apocalyptic number.

638844847407 is a deficient number, since it is larger than the sum of its proper divisors (413869578993).

638844847407 is a wasteful number, since it uses less digits than its factorization.

638844847407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152472 (or 152469 counting only the distinct ones).

The product of its (nonzero) digits is 115605504, while the sum is 63.

The spelling of 638844847407 in words is "six hundred thirty-eight billion, eight hundred forty-four million, eight hundred forty-seven thousand, four hundred seven".