821388960 has 288 divisors, whose sum is σ = 3270758400. Its totient is φ = 187633152.

The previous prime is 821388959. The next prime is 821389001. The reversal of 821388960 is 69883128.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 493089 + ... + 494751.

It is an arithmetic number, because the mean of its divisors is an integer number (11356800).

Almost surely, 2^821388960 is an apocalyptic number.

821388960 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 821388960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1635379200).

821388960 is an abundant number, since it is smaller than the sum of its proper divisors (2449369440).

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

821388960 is a wasteful number, since it uses less digits than its factorization.

821388960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1705 (or 1680 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 821388960 is about 28659.8841588727. The cubic root of 821388960 is about 936.5183409941.

The spelling of 821388960 in words is "eight hundred twenty-one million, three hundred eighty-eight thousand, nine hundred sixty".