18661926889889 has 16 divisors (see below), whose sum is σ = 19347361488000. Its totient is φ = 17979317131776.

The previous prime is 18661926889871. The next prime is 18661926889897. The reversal of 18661926889889 is 98898862916681.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18661926889889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18661326889889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34525937 + ... + 35062289.

It is an arithmetic number, because the mean of its divisors is an integer number (1209210093000).

Almost surely, 2^{18661926889889} is an apocalyptic number.

It is an amenable number.

18661926889889 is a deficient number, since it is larger than the sum of its proper divisors (685434598111).

18661926889889 is a wasteful number, since it uses less digits than its factorization.

18661926889889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 538984.

The product of its digits is 10319560704, while the sum is 89.

The spelling of 18661926889889 in words is "eighteen trillion, six hundred sixty-one billion, nine hundred twenty-six million, eight hundred eighty-nine thousand, eight hundred eighty-nine".