5721921684 has 54 divisors (see below), whose sum is σ = 14865351774. Its totient is φ = 1855742400.

The previous prime is 5721921683. The next prime is 5721921767. The reversal of 5721921684 is 4861291275.

5721921684 is a `hidden beast` number, since 572 + 19 + 2 + 1 + 68 + 4 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 1389649284 + 4332272400 = 37278^2 + 65820^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5721921683) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8767 + ... + 107334.

Almost surely, 2^5721921684 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 5721921684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7432675887).

5721921684 is an abundant number, since it is smaller than the sum of its proper divisors (9143430090).

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

5721921684 is a wasteful number, since it uses less digits than its factorization.

5721921684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116185 (or 116143 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 5721921684 is about 75643.3849321935. The cubic root of 5721921684 is about 1788.6030614429.

The spelling of 5721921684 in words is "five billion, seven hundred twenty-one million, nine hundred twenty-one thousand, six hundred eighty-four".