821323776 has 288 divisors, whose sum is σ = 2733756480. Its totient is φ = 214695936.

The previous prime is 821323753. The next prime is 821323777. The reversal of 821323776 is 677323128.

It is a Harshad number since it is a multiple of its sum of digits (39).

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

It is not an unprimeable number, because it can be changed into a prime (821323777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7268296 + ... + 7268408.

It is an arithmetic number, because the mean of its divisors is an integer number (9492210).

Almost surely, 2^821323776 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 821323776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1366878240).

821323776 is an abundant number, since it is smaller than the sum of its proper divisors (1912432704).

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

821323776 is a wasteful number, since it uses less digits than its factorization.

821323776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 138 counting only the distinct ones).

The product of its digits is 84672, while the sum is 39.

The square root of 821323776 is about 28658.7469370173. The cubic root of 821323776 is about 936.4935668495.

The spelling of 821323776 in words is "eight hundred twenty-one million, three hundred twenty-three thousand, seven hundred seventy-six".