1921682568 has 128 divisors (see below), whose sum is σ = 5423604480. Its totient is φ = 562974720.

The previous prime is 1921682549. The next prime is 1921682597. The reversal of 1921682568 is 8652861291.

It is a Cunningham number, because it is equal to 43837²-1.

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, 2015980 + ... + 2016932.

It is an arithmetic number, because the mean of its divisors is an integer number (42371910).

Almost surely, 2^1921682568 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 1921682568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2711802240).

1921682568 is an abundant number, since it is smaller than the sum of its proper divisors (3501921912).

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

1921682568 is a wasteful number, since it uses less digits than its factorization.

1921682568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1279 (or 1275 counting only the distinct ones).

The product of its digits is 414720, while the sum is 48.

The square root of 1921682568 is about 43836.9999885941. Note that the first 4 decimals coincide. The cubic root of 1921682568 is about 1243.2559609596.

The spelling of 1921682568 in words is "one billion, nine hundred twenty-one million, six hundred eighty-two thousand, five hundred sixty-eight".