646244561128 has 8 divisors (see below), whose sum is σ = 1211708552130. Its totient is φ = 323122280560.

The previous prime is 646244561071. The next prime is 646244561129. The reversal of 646244561128 is 821165442646.

It can be written as a sum of positive squares in only one way, i.e., 620279106084 + 25965455044 = 787578^2 + 161138^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (646244561129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40390285063 + ... + 40390285078.

Almost surely, 2^646244561128 is an apocalyptic number.

It is an amenable number.

646244561128 is a deficient number, since it is larger than the sum of its proper divisors (565463991002).

646244561128 is a wasteful number, since it uses less digits than its factorization.

646244561128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80780570147 (or 80780570143 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 49.

The spelling of 646244561128 in words is "six hundred forty-six billion, two hundred forty-four million, five hundred sixty-one thousand, one hundred twenty-eight".