820033643520 has 1584 divisors, whose sum is σ = 3599765769600. Its totient is φ = 172454510592.

The previous prime is 820033643519. The next prime is 820033643579. The reversal of 820033643520 is 25346330028.

It is a happy number.

820033643520 is a `hidden beast` number, since 8 + 2 + 0 + 0 + 3 + 3 + 643 + 5 + 2 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2671119207 + ... + 2671119513.

It is an arithmetic number, because the mean of its divisors is an integer number (2272579400).

Almost surely, 2^820033643520 is an apocalyptic number.

820033643520 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 820033643520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1799882884800).

820033643520 is an abundant number, since it is smaller than the sum of its proper divisors (2779732126080).

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

820033643520 is a wasteful number, since it uses less digits than its factorization.

820033643520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

Adding to 820033643520 its reverse (25346330028), we get a palindrome (845379973548).

The spelling of 820033643520 in words is "eight hundred twenty billion, thirty-three million, six hundred forty-three thousand, five hundred twenty".