605661656561 has 8 divisors (see below), whose sum is σ = 674742429480. Its totient is φ = 539793942912.

The previous prime is 605661656549. The next prime is 605661656591. The reversal of 605661656561 is 165656166506.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21048496561 + 584613160000 = 145081^2 + 764600^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-605661656561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (605661656591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 803264420 + ... + 803265173.

It is an arithmetic number, because the mean of its divisors is an integer number (84342803685).

Almost surely, 2^605661656561 is an apocalyptic number.

It is an amenable number.

605661656561 is a deficient number, since it is larger than the sum of its proper divisors (69080772919).

605661656561 is a wasteful number, since it uses less digits than its factorization.

605661656561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1606529635.

The product of its (nonzero) digits is 5832000, while the sum is 53.

The spelling of 605661656561 in words is "six hundred five billion, six hundred sixty-one million, six hundred fifty-six thousand, five hundred sixty-one".