819980387820 has 864 divisors, whose sum is σ = 2971877126400. Its totient is φ = 182817423360.

The previous prime is 819980387819. The next prime is 819980387827. The reversal of 819980387820 is 28783089918.

It is not an unprimeable number, because it can be changed into a prime (819980387827) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 8453406012 + ... + 8453406108.

It is an arithmetic number, because the mean of its divisors is an integer number (3439672600).

Almost surely, 2^819980387820 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 819980387820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485938563200).

819980387820 is an abundant number, since it is smaller than the sum of its proper divisors (2151896738580).

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

819980387820 is a wasteful number, since it uses less digits than its factorization.

819980387820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 63.

The spelling of 819980387820 in words is "eight hundred nineteen billion, nine hundred eighty million, three hundred eighty-seven thousand, eight hundred twenty".