163711275561 has 24 divisors (see below), whose sum is σ = 250416044424. Its totient is φ = 102706813440.

The previous prime is 163711275503. The next prime is 163711275593. The reversal of 163711275561 is 165572117361.

163711275561 is a `hidden beast` number, since 1 + 6 + 3 + 7 + 1 + 12 + 75 + 561 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 73842627600 + 89868647961 = 271740^2 + 299781^2 .

It is not a de Polignac number, because 163711275561 - 2²² = 163707081257 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (163711275061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1117851 + ... + 1255791.

It is an arithmetic number, because the mean of its divisors is an integer number (10434001851).

Almost surely, 2^163711275561 is an apocalyptic number.

It is an amenable number.

163711275561 is a deficient number, since it is larger than the sum of its proper divisors (86704768863).

163711275561 is a wasteful number, since it uses less digits than its factorization.

163711275561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145721 (or 145718 counting only the distinct ones).

The product of its digits is 264600, while the sum is 45.

The spelling of 163711275561 in words is "one hundred sixty-three billion, seven hundred eleven million, two hundred seventy-five thousand, five hundred sixty-one".