5781621888 has 640 divisors, whose sum is σ = 21149251200. Its totient is φ = 1532805120.

The previous prime is 5781621863. The next prime is 5781621913. The reversal of 5781621888 is 8881261875.

5781621888 is a `hidden beast` number, since 5 + 7 + 8 + 1 + 621 + 8 + 8 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (5781621863) and next prime (5781621913).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 86292831 + ... + 86292897.

It is an arithmetic number, because the mean of its divisors is an integer number (33045705).

Almost surely, 2^5781621888 is an apocalyptic number.

5781621888 is a gapful number since it is divisible by the number (58) 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 5781621888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10574625600).

5781621888 is an abundant number, since it is smaller than the sum of its proper divisors (15367629312).

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

5781621888 is a wasteful number, since it uses less digits than its factorization.

5781621888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 149 counting only the distinct ones).

The product of its digits is 1720320, while the sum is 54.

The square root of 5781621888 is about 76036.9771098247. The cubic root of 5781621888 is about 1794.8020708556.

The spelling of 5781621888 in words is "five billion, seven hundred eighty-one million, six hundred twenty-one thousand, eight hundred eighty-eight".