821298240 has 168 divisors, whose sum is σ = 3228563520. Its totient is φ = 187720704.

The previous prime is 821298239. The next prime is 821298263. The reversal of 821298240 is 42892128.

821298240 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 821298195 and 821298204.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 210 + ... + 40529.

It is an arithmetic number, because the mean of its divisors is an integer number (19217640).

Almost surely, 2^821298240 is an apocalyptic number.

821298240 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 821298240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1614281760).

821298240 is an abundant number, since it is smaller than the sum of its proper divisors (2407265280).

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

821298240 is a wasteful number, since it uses less digits than its factorization.

821298240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40769 (or 40756 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 821298240 is about 28658.3014151223. The cubic root of 821298240 is about 936.4838611572.

The spelling of 821298240 in words is "eight hundred twenty-one million, two hundred ninety-eight thousand, two hundred forty".