811394781120 has 1120 divisors, whose sum is σ = 3788041720320. Its totient is φ = 159720284160.

The previous prime is 811394781083. The next prime is 811394781167. The reversal of 811394781120 is 21187493118.

It is a happy number.

811394781120 is a `hidden beast` number, since 81 + 1 + 394 + 78 + 112 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

It is a super-2 number, since 2×811394781120² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 37910262 + ... + 37931658.

Almost surely, 2^811394781120 is an apocalyptic number.

811394781120 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 811394781120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1894020860160).

811394781120 is an abundant number, since it is smaller than the sum of its proper divisors (2976646939200).

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

811394781120 is a wasteful number, since it uses less digits than its factorization.

811394781120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21463 (or 21444 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The spelling of 811394781120 in words is "eight hundred eleven billion, three hundred ninety-four million, seven hundred eighty-one thousand, one hundred twenty".