161661110601101 has 2 divisors, whose sum is σ = 161661110601102. Its totient is φ = 161661110601100.

The previous prime is 161661110601019. The next prime is 161661110601131. The reversal of 161661110601101 is 101106011166161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97165771852900 + 64495338748201 = 9857270^2 + 8030899^2 .

It is a cyclic number.

It is not a de Polignac number, because 161661110601101 - 2⁴⁶ = 91292366423437 is a prime.

It is a super-2 number, since 2×161661110601101² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161661110601131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80830555300550 + 80830555300551.

It is an arithmetic number, because the mean of its divisors is an integer number (80830555300551).

Almost surely, 2^{161661110601101} is an apocalyptic number.

It is an amenable number.

161661110601101 is a deficient number, since it is larger than the sum of its proper divisors (1).

161661110601101 is an equidigital number, since it uses as much as digits as its factorization.

161661110601101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 32.

Adding to 161661110601101 its reverse (101106011166161), we get a palindrome (262767121767262).

The spelling of 161661110601101 in words is "one hundred sixty-one trillion, six hundred sixty-one billion, one hundred ten million, six hundred one thousand, one hundred one".