280788361820 has 96 divisors (see below), whose sum is σ = 627032145600. Its totient is φ = 105253908480.

The previous prime is 280788361801. The next prime is 280788361849. The reversal of 280788361820 is 28163887082.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115217642 + ... + 115220078.

It is an arithmetic number, because the mean of its divisors is an integer number (6531584850).

Almost surely, 2^280788361820 is an apocalyptic number.

280788361820 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 280788361820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313516072800).

280788361820 is an abundant number, since it is smaller than the sum of its proper divisors (346243783780).

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

280788361820 is a wasteful number, since it uses less digits than its factorization.

280788361820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3783 (or 3781 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 53.

The spelling of 280788361820 in words is "two hundred eighty billion, seven hundred eighty-eight million, three hundred sixty-one thousand, eight hundred twenty".