18161066169 has 27 divisors (see below), whose sum is σ = 27185968173. Its totient is φ = 11682334944.

The previous prime is 18161066159. The next prime is 18161066177. The reversal of 18161066169 is 96166016181.

It is a happy number.

The square root of 18161066169 is 134763.

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

18161066169 is a `hidden beast` number, since 1 + 8 + 16 + 10 + 6 + 616 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 354832569 + 17806233600 = 18837^2 + 133440^2 .

It is not a de Polignac number, because 18161066169 - 2¹³ = 18161057977 is a prime.

It is a super-2 number, since 2×18161066169² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18161066129) 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 26 ways as a sum of consecutive naturals, for example, 11723607 + ... + 11725155.

Almost surely, 2^18161066169 is an apocalyptic number.

18161066169 is the 134763-rd square number.

18161066169 is the 67382-nd centered octagonal number.

It is an amenable number.

18161066169 is a deficient number, since it is larger than the sum of its proper divisors (9024902004).

18161066169 is an frugal number, since it uses more digits than its factorization.

18161066169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3162 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 18161066169 in words is "eighteen billion, one hundred sixty-one million, sixty-six thousand, one hundred sixty-nine".