161712217161 has 48 divisors (see below), whose sum is σ = 257689111680. Its totient is φ = 96906240000.

The previous prime is 161712217159. The next prime is 161712217187.

161712217161 is a `hidden beast` number, since 1 + 617 + 1 + 2 + 21 + 7 + 16 + 1 = 666.

161712217161 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 161712217161 - 2¹ = 161712217159 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (161712217111) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7678716 + ... + 7699746.

It is an arithmetic number, because the mean of its divisors is an integer number (5368523160).

Almost surely, 2^161712217161 is an apocalyptic number.

161712217161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161712217161 is a deficient number, since it is larger than the sum of its proper divisors (95976894519).

161712217161 is a wasteful number, since it uses less digits than its factorization.

161712217161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21918 (or 21915 counting only the distinct ones).

The product of its digits is 7056, while the sum is 36.

It can be divided in two parts, 161712 and 217161, that added together give a palindrome (378873).

The spelling of 161712217161 in words is "one hundred sixty-one billion, seven hundred twelve million, two hundred seventeen thousand, one hundred sixty-one".