811391040000 has 400 divisors, whose sum is σ = 3001288530240. Its totient is φ = 216368640000.

The previous prime is 811391039959. The next prime is 811391040013. The reversal of 811391040000 is 40193118.

It is a tau number, because it is divible by the number of its divisors (400).

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

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8593045 + ... + 8686955.

Almost surely, 2^811391040000 is an apocalyptic number.

811391040000 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 811391040000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1500644265120).

811391040000 is an abundant number, since it is smaller than the sum of its proper divisors (2189897490240).

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

811391040000 is an frugal number, since it uses more digits than its factorization.

811391040000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93958 (or 93921 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The spelling of 811391040000 in words is "eight hundred eleven billion, three hundred ninety-one million, forty thousand".