18105386661 has 24 divisors (see below), whose sum is σ = 27092033280. Its totient is φ = 11639275200.

The previous prime is 18105386639. The next prime is 18105386669. The reversal of 18105386661 is 16668350181.

It is not a de Polignac number, because 18105386661 - 2¹¹ = 18105384613 is a prime.

It is a super-2 number, since 2×18105386661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18105386669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37071 + ... + 193868.

It is an arithmetic number, because the mean of its divisors is an integer number (1128834720).

Almost surely, 2^18105386661 is an apocalyptic number.

It is an amenable number.

18105386661 is a deficient number, since it is larger than the sum of its proper divisors (8986646619).

18105386661 is a wasteful number, since it uses less digits than its factorization.

18105386661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231257 (or 231254 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 18105386661 in words is "eighteen billion, one hundred five million, three hundred eighty-six thousand, six hundred sixty-one".