1566216171561 has 64 divisors (see below), whose sum is σ = 2250575953920. Its totient is φ = 965333790720.

The previous prime is 1566216171511. The next prime is 1566216171581. The reversal of 1566216171561 is 1651716126651.

It is not a de Polignac number, because 1566216171561 - 2⁷ = 1566216171433 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1566216171561.

It is not an unprimeable number, because it can be changed into a prime (1566216171511) 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 63 ways as a sum of consecutive naturals, for example, 751903026 + ... + 751905108.

It is an arithmetic number, because the mean of its divisors is an integer number (35165249280).

Almost surely, 2^{1566216171561} is an apocalyptic number.

It is an amenable number.

1566216171561 is a deficient number, since it is larger than the sum of its proper divisors (684359782359).

1566216171561 is a wasteful number, since it uses less digits than its factorization.

1566216171561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3046.

The product of its digits is 453600, while the sum is 48.

The spelling of 1566216171561 in words is "one trillion, five hundred sixty-six billion, two hundred sixteen million, one hundred seventy-one thousand, five hundred sixty-one".