18226713555666 has 576 divisors, whose sum is σ = 51963243171840. Its totient is φ = 4563067461120.

The previous prime is 18226713555653. The next prime is 18226713555667. The reversal of 18226713555666 is 66655531762281.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (18226713555667) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 16615052830 + ... + 16615053926.

It is an arithmetic number, because the mean of its divisors is an integer number (90213963840).

Almost surely, 2^{18226713555666} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18226713555666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25981621585920).

18226713555666 is an abundant number, since it is smaller than the sum of its proper divisors (33736529616174).

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

18226713555666 is a wasteful number, since it uses less digits than its factorization.

18226713555666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1699 (or 1689 counting only the distinct ones).

The product of its digits is 108864000, while the sum is 63.

The spelling of 18226713555666 in words is "eighteen trillion, two hundred twenty-six billion, seven hundred thirteen million, five hundred fifty-five thousand, six hundred sixty-six".