2101116561 has 8 divisors (see below), whose sum is σ = 2840946624. Its totient is φ = 1381015440.

The previous prime is 2101116559. The next prime is 2101116569. The reversal of 2101116561 is 1656111012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2101116561 - 2¹ = 2101116559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2101116569) 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 7 ways as a sum of consecutive naturals, for example, 4931986 + ... + 4932411.

It is an arithmetic number, because the mean of its divisors is an integer number (355118328).

Almost surely, 2^2101116561 is an apocalyptic number.

It is an amenable number.

2101116561 is a deficient number, since it is larger than the sum of its proper divisors (739830063).

2101116561 is an equidigital number, since it uses as much as digits as its factorization.

2101116561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9864471.

The product of its (nonzero) digits is 360, while the sum is 24.

The square root of 2101116561 is about 45837.9380099062. The cubic root of 2101116561 is about 1280.8060842595.

Adding to 2101116561 its reverse (1656111012), we get a palindrome (3757227573).

The spelling of 2101116561 in words is "two billion, one hundred one million, one hundred sixteen thousand, five hundred sixty-one".