285785099820 has 144 divisors (see below), whose sum is σ = 951713407008. Its totient is φ = 68839879680.

The previous prime is 285785099819. The next prime is 285785099827. The reversal of 285785099820 is 28990587582.

285785099820 is a `hidden beast` number, since 2 + 8 + 578 + 50 + 9 + 9 + 8 + 2 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (285785099827) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 148809 + ... + 770528.

It is an arithmetic number, because the mean of its divisors is an integer number (6609120882).

Almost surely, 2^285785099820 is an apocalyptic number.

285785099820 is a gapful number since it is divisible by the number (20) 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 285785099820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (475856703504).

285785099820 is an abundant number, since it is smaller than the sum of its proper divisors (665928307188).

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

285785099820 is a wasteful number, since it uses less digits than its factorization.

285785099820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919520 (or 919515 counting only the distinct ones).

The product of its (nonzero) digits is 29030400, while the sum is 63.

The spelling of 285785099820 in words is "two hundred eighty-five billion, seven hundred eighty-five million, ninety-nine thousand, eight hundred twenty".