1813351385664 has 1260 divisors, whose sum is σ = 6907353583284. Its totient is φ = 468634263552.

The previous prime is 1813351385653. The next prime is 1813351385669. The reversal of 1813351385664 is 4665831533181.

1813351385664 is a `hidden beast` number, since 1 + 8 + 13 + 3 + 513 + 8 + 56 + 64 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 142122968064 + 1671228417600 = 376992^2 + 1292760^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 1813351385664.

It is not an unprimeable number, because it can be changed into a prime (1813351385669) by changing a digit.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 2275220914 + ... + 2275221710.

Almost surely, 2^{1813351385664} is an apocalyptic number.

1813351385664 is a gapful number since it is divisible by the number (14) 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 1813351385664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3453676791642).

1813351385664 is an abundant number, since it is smaller than the sum of its proper divisors (5094002197620).

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

1813351385664 is a wasteful number, since it uses less digits than its factorization.

1813351385664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914 (or 875 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 54.

The spelling of 1813351385664 in words is "one trillion, eight hundred thirteen billion, three hundred fifty-one million, three hundred eighty-five thousand, six hundred sixty-four".