1611111561101 has 4 divisors (see below), whose sum is σ = 1841270355552. Its totient is φ = 1380952766652.

The previous prime is 1611111561071. The next prime is 1611111561109. The reversal of 1611111561101 is 1011651111161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1611111561101 - 2¹⁴ = 1611111544717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611111561109) 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, 115079397215 + ... + 115079397228.

It is an arithmetic number, because the mean of its divisors is an integer number (460317588888).

Almost surely, 2^{1611111561101} is an apocalyptic number.

It is an amenable number.

1611111561101 is a deficient number, since it is larger than the sum of its proper divisors (230158794451).

1611111561101 is an equidigital number, since it uses as much as digits as its factorization.

1611111561101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230158794450.

The product of its (nonzero) digits is 180, while the sum is 26.

Adding to 1611111561101 its reverse (1011651111161), we get a palindrome (2622762672262).

The spelling of 1611111561101 in words is "one trillion, six hundred eleven billion, one hundred eleven million, five hundred sixty-one thousand, one hundred one".