820618905600 has 1440 divisors, whose sum is σ = 3385665803520. Its totient is φ = 195084288000.

The previous prime is 820618905577. The next prime is 820618905607. The reversal of 820618905600 is 6509816028.

820618905600 is a `hidden beast` number, since 8 + 2 + 0 + 6 + 1 + 89 + 0 + 560 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a super-2 number, since 2×820618905600² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820618905607) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1671321355 + ... + 1671321845.

It is an arithmetic number, because the mean of its divisors is an integer number (2351156808).

Almost surely, 2^820618905600 is an apocalyptic number.

820618905600 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 820618905600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1692832901760).

820618905600 is an abundant number, since it is smaller than the sum of its proper divisors (2565046897920).

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

820618905600 is a wasteful number, since it uses less digits than its factorization.

820618905600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 545 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 820618905600 in words is "eight hundred twenty billion, six hundred eighteen million, nine hundred five thousand, six hundred".