821550240 has 288 divisors, whose sum is σ = 3231446400. Its totient is φ = 186181632.

The previous prime is 821550221. The next prime is 821550263. The reversal of 821550240 is 42055128.

It is a happy number.

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

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, 1501647 + ... + 1502193.

It is an arithmetic number, because the mean of its divisors is an integer number (11220300).

Almost surely, 2^821550240 is an apocalyptic number.

821550240 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 821550240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1615723200).

821550240 is an abundant number, since it is smaller than the sum of its proper divisors (2409896160).

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

821550240 is a wasteful number, since it uses less digits than its factorization.

821550240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 821550240 is about 28662.6977097411. The cubic root of 821550240 is about 936.5796322137.

The spelling of 821550240 in words is "eight hundred twenty-one million, five hundred fifty thousand, two hundred forty".