1566606355561 has 32 divisors (see below), whose sum is σ = 1864870318080. Its totient is φ = 1301267303424.

The previous prime is 1566606355513. The next prime is 1566606355571. The reversal of 1566606355561 is 1655536066651.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1566606355561 - 2¹⁵ = 1566606322793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1566606355571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11312011 + ... + 11449663.

It is an arithmetic number, because the mean of its divisors is an integer number (58277197440).

Almost surely, 2^{1566606355561} is an apocalyptic number.

It is an amenable number.

1566606355561 is a deficient number, since it is larger than the sum of its proper divisors (298263962519).

1566606355561 is a wasteful number, since it uses less digits than its factorization.

1566606355561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139945.

The product of its (nonzero) digits is 14580000, while the sum is 55.

The spelling of 1566606355561 in words is "one trillion, five hundred sixty-six billion, six hundred six million, three hundred fifty-five thousand, five hundred sixty-one".