18665490861 has 6 divisors (see below), whose sum is σ = 26961264590. Its totient is φ = 12443660568.

The previous prime is 18665490859. The next prime is 18665490911. The reversal of 18665490861 is 16809456681.

18665490861 is a `hidden beast` number, since 18 + 6 + 6 + 549 + 0 + 86 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18307713636 + 357777225 = 135306^2 + 18915^2 .

It is not a de Polignac number, because 18665490861 - 2¹ = 18665490859 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18665490798 and 18665490807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18665492861) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1036971706 + ... + 1036971723.

Almost surely, 2^18665490861 is an apocalyptic number.

It is an amenable number.

18665490861 is a deficient number, since it is larger than the sum of its proper divisors (8295773729).

18665490861 is a wasteful number, since it uses less digits than its factorization.

18665490861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2073943435 (or 2073943432 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 18665490861 in words is "eighteen billion, six hundred sixty-five million, four hundred ninety thousand, eight hundred sixty-one".