18661793138688 has 96 divisors (see below), whose sum is σ = 56860151100480. Its totient is φ = 5331940884480.

The previous prime is 18661793138591. The next prime is 18661793138689. The reversal of 18661793138688 is 88683139716681.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×18661793138688² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18661793138689) 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, 216914223 + ... + 217000238.

It is an arithmetic number, because the mean of its divisors is an integer number (592293240630).

Almost surely, 2^{18661793138688} is an apocalyptic number.

It is an amenable number.

18661793138688 is an abundant number, since it is smaller than the sum of its proper divisors (38198357961792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18661793138688 is an equidigital number, since it uses as much as digits as its factorization.

18661793138688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433914493 (or 433914473 counting only the distinct ones).

The product of its digits is 501645312, while the sum is 75.

The spelling of 18661793138688 in words is "eighteen trillion, six hundred sixty-one billion, seven hundred ninety-three million, one hundred thirty-eight thousand, six hundred eighty-eight".