18217857798 has 256 divisors, whose sum is σ = 50388480000. Its totient is φ = 4760930304.

The previous prime is 18217857769. The next prime is 18217857821. The reversal of 18217857798 is 89775871281.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 50745943 + ... + 50746301.

It is an arithmetic number, because the mean of its divisors is an integer number (196830000).

Almost surely, 2^18217857798 is an apocalyptic number.

18217857798 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18217857798, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25194240000).

18217857798 is an abundant number, since it is smaller than the sum of its proper divisors (32170622202).

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

18217857798 is a wasteful number, since it uses less digits than its factorization.

18217857798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596 (or 590 counting only the distinct ones).

The product of its digits is 15805440, while the sum is 63.

The spelling of 18217857798 in words is "eighteen billion, two hundred seventeen million, eight hundred fifty-seven thousand, seven hundred ninety-eight".