61665566016611 has 4 divisors (see below), whose sum is σ = 63791964844800. Its totient is φ = 59539167188424.

The previous prime is 61665566016601. The next prime is 61665566016631. The reversal of 61665566016611 is 11661066556616.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61665566016611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61665566016601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1063199414051 + ... + 1063199414108.

It is an arithmetic number, because the mean of its divisors is an integer number (15947991211200).

Almost surely, 2^{61665566016611} is an apocalyptic number.

61665566016611 is a deficient number, since it is larger than the sum of its proper divisors (2126398828189).

61665566016611 is a wasteful number, since it uses less digits than its factorization.

61665566016611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2126398828188.

The product of its (nonzero) digits is 6998400, while the sum is 56.

The spelling of 61665566016611 in words is "sixty-one trillion, six hundred sixty-five billion, five hundred sixty-six million, sixteen thousand, six hundred eleven".