106561566665 has 4 divisors (see below), whose sum is σ = 127873880004. Its totient is φ = 85249253328.

The previous prime is 106561566647. The next prime is 106561566673. The reversal of 106561566665 is 566665165601.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566665165601 = 31 ⋅18279521471.

It can be written as a sum of positive squares in 2 ways, for example, as 28562014009 + 77999552656 = 169003^2 + 279284^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-106561566665 is a prime.

It is a super-2 number, since 2×106561566665² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10656156662 + ... + 10656156671.

It is an arithmetic number, because the mean of its divisors is an integer number (31968470001).

Almost surely, 2^106561566665 is an apocalyptic number.

It is an amenable number.

106561566665 is a deficient number, since it is larger than the sum of its proper divisors (21312313339).

106561566665 is an equidigital number, since it uses as much as digits as its factorization.

106561566665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21312313338.

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

The spelling of 106561566665 in words is "one hundred six billion, five hundred sixty-one million, five hundred sixty-six thousand, six hundred sixty-five".