811991448 has 192 divisors, whose sum is σ = 2446329600. Its totient is φ = 242161920.

The previous prime is 811991437. The next prime is 811991449. The reversal of 811991448 is 844199118.

811991448 is a `hidden beast` number, since 8 + 119 + 91 + 448 = 666.

It is a super-2 number, since 2×811991448² = 1318660223250273408, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811991449) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4121686 + ... + 4121882.

It is an arithmetic number, because the mean of its divisors is an integer number (12741300).

Almost surely, 2^811991448 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 811991448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1223164800).

811991448 is an abundant number, since it is smaller than the sum of its proper divisors (1634338152).

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

811991448 is a wasteful number, since it uses less digits than its factorization.

811991448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382 (or 375 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The square root of 811991448 is about 28495.4636389724. The cubic root of 811991448 is about 932.9330638524.

The spelling of 811991448 in words is "eight hundred eleven million, nine hundred ninety-one thousand, four hundred forty-eight".