161181211 has 4 divisors (see below), whose sum is σ = 161286552. Its totient is φ = 161075872.

The previous prime is 161181193. The next prime is 161181227. The reversal of 161181211 is 112181161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 112181161 = 457 ⋅245473.

It is a cyclic number.

It is not a de Polignac number, because 161181211 - 2⁹ = 161180699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161181281) 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, 50341 + ... + 53446.

It is an arithmetic number, because the mean of its divisors is an integer number (40321638).

Almost surely, 2^161181211 is an apocalyptic number.

161181211 is a deficient number, since it is larger than the sum of its proper divisors (105341).

161181211 is a wasteful number, since it uses less digits than its factorization.

161181211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105340.

The product of its digits is 96, while the sum is 22.

The square root of 161181211 is about 12695.7162460414. The cubic root of 161181211 is about 544.2162074469.

Subtracting from 161181211 its reverse (112181161), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 161181211 in words is "one hundred sixty-one million, one hundred eighty-one thousand, two hundred eleven".