821508480 has 640 divisors, whose sum is σ = 3358998720. Its totient is φ = 189775872.

The previous prime is 821508473. The next prime is 821508481. The reversal of 821508480 is 84805128.

It is a tau number, because it is divible by the number of its divisors (640).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821508481) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 15500134 + ... + 15500186.

Almost surely, 2^821508480 is an apocalyptic number.

821508480 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 821508480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1679499360).

821508480 is an abundant number, since it is smaller than the sum of its proper divisors (2537490240).

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

821508480 is a wasteful number, since it uses less digits than its factorization.

821508480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 821508480 is about 28661.9692275322. The cubic root of 821508480 is about 936.5637629354.

The spelling of 821508480 in words is "eight hundred twenty-one million, five hundred eight thousand, four hundred eighty".