18189694561 has 8 divisors (see below), whose sum is σ = 19274302080. Its totient is φ = 17106712128.

The previous prime is 18189694559. The next prime is 18189694577. The reversal of 18189694561 is 16549698181.

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

It is not a de Polignac number, because 18189694561 - 2¹ = 18189694559 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18189694496 and 18189694505.

It is not an unprimeable number, because it can be changed into a prime (18189694591) 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, 383181 + ... + 428026.

It is an arithmetic number, because the mean of its divisors is an integer number (2409287760).

Almost surely, 2^18189694561 is an apocalyptic number.

It is an amenable number.

18189694561 is a deficient number, since it is larger than the sum of its proper divisors (1084607519).

18189694561 is a wasteful number, since it uses less digits than its factorization.

18189694561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812543.

The product of its digits is 3732480, while the sum is 58.

The spelling of 18189694561 in words is "eighteen billion, one hundred eighty-nine million, six hundred ninety-four thousand, five hundred sixty-one".