20581784244 has 144 divisors (see below), whose sum is σ = 61974814720. Its totient is φ = 5635344960.

The previous prime is 20581784233. The next prime is 20581784273. The reversal of 20581784244 is 44248718502.

20581784244 is a `hidden beast` number, since 2 + 0 + 58 + 178 + 424 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20581784244.

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, 791847 + ... + 817425.

Almost surely, 2^20581784244 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 20581784244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30987407360).

20581784244 is an abundant number, since it is smaller than the sum of its proper divisors (41393030476).

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

20581784244 is a wasteful number, since it uses less digits than its factorization.

20581784244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25730 (or 25725 counting only the distinct ones).

The product of its (nonzero) digits is 573440, while the sum is 45.

The spelling of 20581784244 in words is "twenty billion, five hundred eighty-one million, seven hundred eighty-four thousand, two hundred forty-four".