18361981965312 has 264 divisors, whose sum is σ = 54171460042752. Its totient is φ = 5988766924800.

The previous prime is 18361981965307. The next prime is 18361981965317. The reversal of 18361981965312 is 21356918916381.

18361981965312 is a `hidden beast` number, since 1 + 8 + 3 + 6 + 1 + 9 + 8 + 1 + 96 + 531 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (18361981965307) and next prime (18361981965317).

It is a self number, because there is not a number n which added to its sum of digits gives 18361981965312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18361981965317) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 107290113 + ... + 107461119.

Almost surely, 2^{18361981965312} is an apocalyptic number.

18361981965312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18361981965312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27085730021376).

18361981965312 is an abundant number, since it is smaller than the sum of its proper divisors (35809478077440).

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

18361981965312 is a wasteful number, since it uses less digits than its factorization.

18361981965312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171285 (or 171264 counting only the distinct ones).

The product of its digits is 16796160, while the sum is 63.

The spelling of 18361981965312 in words is "eighteen trillion, three hundred sixty-one billion, nine hundred eighty-one million, nine hundred sixty-five thousand, three hundred twelve".