821391360 has 208 divisors, whose sum is σ = 2724654240. Its totient is φ = 211025920.

The previous prime is 821391349. The next prime is 821391367. The reversal of 821391360 is 63193128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821391367) 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 15 ways as a sum of consecutive naturals, for example, 1781530 + ... + 1781990.

Almost surely, 2^821391360 is an apocalyptic number.

821391360 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 821391360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1362327120).

821391360 is an abundant number, since it is smaller than the sum of its proper divisors (1903262880).

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

821391360 is a wasteful number, since it uses less digits than its factorization.

821391360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 821391360 is about 28659.9260292137. The cubic root of 821391360 is about 936.5192531246.

The spelling of 821391360 in words is "eight hundred twenty-one million, three hundred ninety-one thousand, three hundred sixty".