812665988640 has 1008 divisors, whose sum is σ = 3212566515648. Its totient is φ = 193995648000.

The previous prime is 812665988609. The next prime is 812665988647. The reversal of 812665988640 is 46889566218.

812665988640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (812665988647) by changing a digit.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 1002053835 + ... + 1002054645.

It is an arithmetic number, because the mean of its divisors is an integer number (3187069956).

Almost surely, 2^812665988640 is an apocalyptic number.

812665988640 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 812665988640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1606283257824).

812665988640 is an abundant number, since it is smaller than the sum of its proper divisors (2399900527008).

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

812665988640 is a wasteful number, since it uses less digits than its factorization.

812665988640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937 (or 903 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 63.

The spelling of 812665988640 in words is "eight hundred twelve billion, six hundred sixty-five million, nine hundred eighty-eight thousand, six hundred forty".