105556100561 has 4 divisors (see below), whose sum is σ = 105557172324. Its totient is φ = 105555028800.

The previous prime is 105556100537. The next prime is 105556100569. The reversal of 105556100561 is 165001655501.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 165001655501 = 1019 ⋅161925079.

It can be written as a sum of positive squares in 2 ways, for example, as 98806492225 + 6749608336 = 314335^2 + 82156^2 .

It is a cyclic number.

It is not a de Polignac number, because 105556100561 - 2¹⁴ = 105556084177 is a prime.

It is a super-2 number, since 2×105556100561² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105556100569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 371300 + ... + 590741.

It is an arithmetic number, because the mean of its divisors is an integer number (26389293081).

Almost surely, 2^105556100561 is an apocalyptic number.

It is an amenable number.

105556100561 is a deficient number, since it is larger than the sum of its proper divisors (1071763).

105556100561 is an equidigital number, since it uses as much as digits as its factorization.

105556100561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071762.

The product of its (nonzero) digits is 22500, while the sum is 35.

It can be divided in two parts, 10555 and 6100561, that added together give a palindrome (6111116).

The spelling of 105556100561 in words is "one hundred five billion, five hundred fifty-six million, one hundred thousand, five hundred sixty-one".