22161979161 has 135 divisors (see below), whose sum is σ = 41206312719. Its totient is φ = 11833299072.

The previous prime is 22161979139. The next prime is 22161979187. The reversal of 22161979161 is 16197916122.

The square root of 22161979161 is 148869.

It is a perfect power (a square), and thus also a powerful number.

22161979161 is a `hidden beast` number, since 2 + 21 + 619 + 7 + 9 + 1 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17254136025 + 4907843136 = 131355^2 + 70056^2 .

It is not a de Polignac number, because 22161979161 - 2⁷ = 22161979033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (22161979111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 159438630 + ... + 159438768.

Almost surely, 2^22161979161 is an apocalyptic number.

22161979161 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

22161979161 is the 148869-th square number.

22161979161 is the 74435-th centered octagonal number.

It is an amenable number.

22161979161 is a deficient number, since it is larger than the sum of its proper divisors (19044333558).

22161979161 is an equidigital number, since it uses as much as digits as its factorization.

22161979161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 166 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The spelling of 22161979161 in words is "twenty-two billion, one hundred sixty-one million, nine hundred seventy-nine thousand, one hundred sixty-one".