561643777442628 has 84 divisors (see below), whose sum is σ = 1475603032989568. Its totient is φ = 186965304678000.

The previous prime is 561643777442549. The next prime is 561643777442639. The reversal of 561643777442628 is 826244777346165.

561643777442628 is a `hidden beast` number, since 5 + 6 + 1 + 6 + 43 + 77 + 74 + 426 + 28 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 126044176 + ... + 130424007.

Almost surely, 2^{561643777442628} is an apocalyptic number.

It is an amenable number.

561643777442628 is an abundant number, since it is smaller than the sum of its proper divisors (913959255546940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561643777442628 is a wasteful number, since it uses less digits than its factorization.

561643777442628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256468956 (or 256468939 counting only the distinct ones).

The product of its digits is 2275983360, while the sum is 72.

The spelling of 561643777442628 in words is "five hundred sixty-one trillion, six hundred forty-three billion, seven hundred seventy-seven million, four hundred forty-two thousand, six hundred twenty-eight".