1816328999808 has 96 divisors (see below), whose sum is σ = 5234134253400. Its totient is φ = 604579046400.

The previous prime is 1816328999783. The next prime is 1816328999809. The reversal of 1816328999808 is 8089998236181.

1816328999808 is a `hidden beast` number, since 181 + 6 + 3 + 289 + 99 + 80 + 8 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816328999809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 317038 + ... + 1932141.

Almost surely, 2^{1816328999808} is an apocalyptic number.

1816328999808 is a gapful number since it is divisible by the number (18) 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 1816328999808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2617067126700).

1816328999808 is an abundant number, since it is smaller than the sum of its proper divisors (3417805253592).

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

1816328999808 is a wasteful number, since it uses less digits than its factorization.

1816328999808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2249900 (or 2249885 counting only the distinct ones).

The product of its (nonzero) digits is 107495424, while the sum is 72.

The spelling of 1816328999808 in words is "one trillion, eight hundred sixteen billion, three hundred twenty-eight million, nine hundred ninety-nine thousand, eight hundred eight".