655781780061 has 48 divisors (see below), whose sum is σ = 991794585600. Its totient is φ = 416756399136.

The previous prime is 655781780021. The next prime is 655781780063. The reversal of 655781780061 is 160087187556.

655781780061 is a `hidden beast` number, since 6 + 5 + 578 + 1 + 7 + 8 + 0 + 0 + 61 = 666.

It is not a de Polignac number, because 655781780061 - 2⁶ = 655781779997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655781780063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 83185426 + ... + 83193308.

It is an arithmetic number, because the mean of its divisors is an integer number (20662387200).

Almost surely, 2^655781780061 is an apocalyptic number.

It is an amenable number.

655781780061 is a deficient number, since it is larger than the sum of its proper divisors (336012805539).

655781780061 is a wasteful number, since it uses less digits than its factorization.

655781780061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9230 (or 9227 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 655781780061 in words is "six hundred fifty-five billion, seven hundred eighty-one million, seven hundred eighty thousand, sixty-one".