640123404442 has 16 divisors (see below), whose sum is σ = 995454919872. Its totient is φ = 308493203680.

The previous prime is 640123404391. The next prime is 640123404463. The reversal of 640123404442 is 244404321046.

It is a junction number, because it is equal to n+sod(n) for n = 640123404398 and 640123404407.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47019598 + ... + 47033209.

It is an arithmetic number, because the mean of its divisors is an integer number (62215932492).

Almost surely, 2^640123404442 is an apocalyptic number.

640123404442 is a deficient number, since it is larger than the sum of its proper divisors (355331515430).

640123404442 is a wasteful number, since it uses less digits than its factorization.

640123404442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94052933.

The product of its (nonzero) digits is 73728, while the sum is 34.

Adding to 640123404442 its reverse (244404321046), we get a palindrome (884527725488).

The spelling of 640123404442 in words is "six hundred forty billion, one hundred twenty-three million, four hundred four thousand, four hundred forty-two".