821727744 has 80 divisors (see below), whose sum is σ = 2214099360. Its totient is φ = 270786560.

The previous prime is 821727727. The next prime is 821727749. The reversal of 821727744 is 447727128.

It is a junction number, because it is equal to n+sod(n) for n = 821727696 and 821727705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821727749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133699 + ... + 139709.

It is an arithmetic number, because the mean of its divisors is an integer number (27676242).

Almost surely, 2^821727744 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 821727744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107049680).

821727744 is an abundant number, since it is smaller than the sum of its proper divisors (1392371616).

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

821727744 is an equidigital number, since it uses as much as digits as its factorization.

821727744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6121 (or 6105 counting only the distinct ones).

The product of its digits is 175616, while the sum is 42.

The square root of 821727744 is about 28665.7939712124. The cubic root of 821727744 is about 936.6470797664.

The spelling of 821727744 in words is "eight hundred twenty-one million, seven hundred twenty-seven thousand, seven hundred forty-four".