820818327780 has 864 divisors, whose sum is σ = 2989343605248. Its totient is φ = 180628531200.

The previous prime is 820818327779. The next prime is 820818327829. The reversal of 820818327780 is 87723818028.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1780516750 + ... + 1780517210.

It is an arithmetic number, because the mean of its divisors is an integer number (3459888432).

Almost surely, 2^820818327780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820818327780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1494671802624).

820818327780 is an abundant number, since it is smaller than the sum of its proper divisors (2168525277468).

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

820818327780 is a wasteful number, since it uses less digits than its factorization.

820818327780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 2408448, while the sum is 54.

The spelling of 820818327780 in words is "eight hundred twenty billion, eight hundred eighteen million, three hundred twenty-seven thousand, seven hundred eighty".