820778206320 has 240 divisors, whose sum is σ = 2919365336160. Its totient is φ = 205944569856.

The previous prime is 820778206289. The next prime is 820778206351. The reversal of 820778206320 is 23602877028.

820778206320 is a `hidden beast` number, since 8 + 2 + 0 + 7 + 7 + 8 + 2 + 0 + 632 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (820778206289) and next prime (820778206351).

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

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, 66297891 + ... + 66310269.

It is an arithmetic number, because the mean of its divisors is an integer number (12164022234).

Almost surely, 2^820778206320 is an apocalyptic number.

820778206320 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 820778206320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1459682668080).

820778206320 is an abundant number, since it is smaller than the sum of its proper divisors (2098587129840).

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

820778206320 is a wasteful number, since it uses less digits than its factorization.

820778206320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17832 (or 17823 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The spelling of 820778206320 in words is "eight hundred twenty billion, seven hundred seventy-eight million, two hundred six thousand, three hundred twenty".