161181111212 has 36 divisors (see below), whose sum is σ = 326874710904. Its totient is φ = 68954480640.

The previous prime is 161181111211. The next prime is 161181111307. The reversal of 161181111212 is 212111181161.

It is a super-2 number, since 2×161181111212² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161181111211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6325013 + ... + 6350444.

Almost surely, 2^161181111212 is an apocalyptic number.

It is an amenable number.

161181111212 is an abundant number, since it is smaller than the sum of its proper divisors (165693599692).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161181111212 is a wasteful number, since it uses less digits than its factorization.

161181111212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12675506 (or 12675487 counting only the distinct ones).

The product of its digits is 192, while the sum is 26.

Adding to 161181111212 its reverse (212111181161), we get a palindrome (373292292373).

The spelling of 161181111212 in words is "one hundred sixty-one billion, one hundred eighty-one million, one hundred eleven thousand, two hundred twelve".