813645000000 has 1680 divisors, whose sum is σ = 3592627326288. Its totient is φ = 181440000000.

The previous prime is 813644999977. The next prime is 813645000019. The reversal of 813645000000 is 546318.

813645000000 is a `hidden beast` number, since 8 + 13 + 645 + 0 + 0 + 0 + 0 + 0 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 412287273216 + 401357726784 = 642096^2 + 633528^2 .

It is a tau number, because it is divible by the number of its divisors (1680).

It is a super-3 number, since 3×813645000000³ (a number of 37 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 19844999980 + ... + 19845000020.

Almost surely, 2^813645000000 is an apocalyptic number.

813645000000 is a gapful number since it is divisible by the number (80) 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 813645000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1796313663144).

813645000000 is an abundant number, since it is smaller than the sum of its proper divisors (2778982326288).

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

813645000000 is an frugal number, since it uses more digits than its factorization.

813645000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 813645000000 its reverse (546318), we get a palindrome (813645546318).

The spelling of 813645000000 in words is "eight hundred thirteen billion, six hundred forty-five million", and thus it is an aban number.