638844531458 has 32 divisors (see below), whose sum is σ = 1122663144960. Its totient is φ = 266924643840.

The previous prime is 638844531401. The next prime is 638844531463. The reversal of 638844531458 is 854135448836.

It is a junction number, because it is equal to n+sod(n) for n = 638844531397 and 638844531406.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 425738 + ... + 1207866.

It is an arithmetic number, because the mean of its divisors is an integer number (35083223280).

Almost surely, 2^638844531458 is an apocalyptic number.

638844531458 is a deficient number, since it is larger than the sum of its proper divisors (483818613502).

638844531458 is a wasteful number, since it uses less digits than its factorization.

638844531458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783602.

The product of its digits is 44236800, while the sum is 59.

The spelling of 638844531458 in words is "six hundred thirty-eight billion, eight hundred forty-four million, five hundred thirty-one thousand, four hundred fifty-eight".