18165656181 has 8 divisors (see below), whose sum is σ = 24736212864. Its totient is φ = 11852768480.

The previous prime is 18165656177. The next prime is 18165656207.

18165656181 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18165656181 - 2² = 18165656177 is a prime.

It is a super-2 number, since 2×18165656181² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 18165656181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18165656111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64417080 + ... + 64417361.

It is an arithmetic number, because the mean of its divisors is an integer number (3092026608).

Almost surely, 2^18165656181 is an apocalyptic number.

It is an amenable number.

18165656181 is a deficient number, since it is larger than the sum of its proper divisors (6570556683).

18165656181 is a wasteful number, since it uses less digits than its factorization.

18165656181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128834491.

The product of its digits is 345600, while the sum is 48.

The spelling of 18165656181 in words is "eighteen billion, one hundred sixty-five million, six hundred fifty-six thousand, one hundred eighty-one".