640123131555142 has 32 divisors (see below), whose sum is σ = 987544148859072. Its totient is φ = 310966646120064.

The previous prime is 640123131555137. The next prime is 640123131555161. The reversal of 640123131555142 is 241555131321046.

It is a congruent number.

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, 245954383 + ... + 248543365.

It is an arithmetic number, because the mean of its divisors is an integer number (30860754651846).

Almost surely, 2^{640123131555142} is an apocalyptic number.

640123131555142 is a deficient number, since it is larger than the sum of its proper divisors (347421017303930).

640123131555142 is a wasteful number, since it uses less digits than its factorization.

640123131555142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2593792.

The product of its (nonzero) digits is 432000, while the sum is 43.

Adding to 640123131555142 its reverse (241555131321046), we get a palindrome (881678262876188).

The spelling of 640123131555142 in words is "six hundred forty trillion, one hundred twenty-three billion, one hundred thirty-one million, five hundred fifty-five thousand, one hundred forty-two".