642126118 has 4 divisors (see below), whose sum is σ = 963189180. Its totient is φ = 321063058.

The previous prime is 642126113. The next prime is 642126127. The reversal of 642126118 is 811621246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 811621246 = 2 ⋅405810623.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 642126118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642126113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160531528 + ... + 160531531.

It is an arithmetic number, because the mean of its divisors is an integer number (240797295).

Almost surely, 2^642126118 is an apocalyptic number.

642126118 is a deficient number, since it is larger than the sum of its proper divisors (321063062).

642126118 is a wasteful number, since it uses less digits than its factorization.

642126118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321063061.

The product of its digits is 4608, while the sum is 31.

The square root of 642126118 is about 25340.2075366403. The cubic root of 642126118 is about 862.7271092196.

The spelling of 642126118 in words is "six hundred forty-two million, one hundred twenty-six thousand, one hundred eighteen".