811947444 has 144 divisors (see below), whose sum is σ = 2531128320. Its totient is φ = 199765440.

The previous prime is 811947427. The next prime is 811947469. The reversal of 811947444 is 444749118.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 811947396 and 811947405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119589 + ... + 126195.

It is an arithmetic number, because the mean of its divisors is an integer number (17577280).

Almost surely, 2^811947444 is an apocalyptic number.

811947444 is a gapful number since it is divisible by the number (84) 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 811947444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1265564160).

811947444 is an abundant number, since it is smaller than the sum of its proper divisors (1719180876).

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

811947444 is a wasteful number, since it uses less digits than its factorization.

811947444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6658 (or 6649 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 811947444 is about 28494.6915056121. The cubic root of 811947444 is about 932.9162108309.

The spelling of 811947444 in words is "eight hundred eleven million, nine hundred forty-seven thousand, four hundred forty-four".