161863818109055 has 16 divisors (see below), whose sum is σ = 196541243242560. Its totient is φ = 127956424265472.

The previous prime is 161863818108991. The next prime is 161863818109061. The reversal of 161863818109055 is 550901818368161.

It is a cyclic number.

It is not a de Polignac number, because 161863818109055 - 2⁶ = 161863818108991 is a prime.

It is a super-2 number, since 2×161863818109055² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112458164 + ... + 113888393.

It is an arithmetic number, because the mean of its divisors is an integer number (12283827702660).

Almost surely, 2^{161863818109055} is an apocalyptic number.

161863818109055 is a deficient number, since it is larger than the sum of its proper divisors (34677425133505).

161863818109055 is a wasteful number, since it uses less digits than its factorization.

161863818109055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226348258.

The product of its (nonzero) digits is 12441600, while the sum is 62.

The spelling of 161863818109055 in words is "one hundred sixty-one trillion, eight hundred sixty-three billion, eight hundred eighteen million, one hundred nine thousand, fifty-five".