18138702216491 has 8 divisors (see below), whose sum is σ = 19220223470544. Its totient is φ = 17058796381440.

The previous prime is 18138702216421. The next prime is 18138702216493. The reversal of 18138702216491 is 19461220783181.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18138702216491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18138702216493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 403831625 + ... + 403876538.

It is an arithmetic number, because the mean of its divisors is an integer number (2402527933818).

Almost surely, 2^{18138702216491} is an apocalyptic number.

18138702216491 is a deficient number, since it is larger than the sum of its proper divisors (1081521254053).

18138702216491 is a wasteful number, since it uses less digits than its factorization.

18138702216491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807709501.

The product of its (nonzero) digits is 1161216, while the sum is 53.

The spelling of 18138702216491 in words is "eighteen trillion, one hundred thirty-eight billion, seven hundred two million, two hundred sixteen thousand, four hundred ninety-one".