820955520 has 512 divisors, whose sum is σ = 3630873600. Its totient is φ = 170311680.

The previous prime is 820955501. The next prime is 820955543. The reversal of 820955520 is 25559028.

820955520 is a `hidden beast` number, since 82 + 0 + 9 + 55 + 520 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1330252 + ... + 1330868.

It is an arithmetic number, because the mean of its divisors is an integer number (7091550).

Almost surely, 2^820955520 is an apocalyptic number.

820955520 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 820955520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1815436800).

820955520 is an abundant number, since it is smaller than the sum of its proper divisors (2809918080).

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

820955520 is a wasteful number, since it uses less digits than its factorization.

820955520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663 (or 645 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The square root of 820955520 is about 28652.3213719238. The cubic root of 820955520 is about 936.3535810767.

The spelling of 820955520 in words is "eight hundred twenty million, nine hundred fifty-five thousand, five hundred twenty".