1921445568 has 168 divisors, whose sum is σ = 6324782880. Its totient is φ = 546324480.

The previous prime is 1921445563. The next prime is 1921445579. The reversal of 1921445568 is 8655441291.

1921445568 is a `hidden beast` number, since 1 + 92 + 1 + 4 + 4 + 556 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is not an unprimeable number, because it can be changed into a prime (1921445563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 922288 + ... + 924368.

Almost surely, 2^1921445568 is an apocalyptic number.

1921445568 is a gapful number since it is divisible by the number (18) 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 1921445568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3162391440).

1921445568 is an abundant number, since it is smaller than the sum of its proper divisors (4403337312).

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

1921445568 is a wasteful number, since it uses less digits than its factorization.

1921445568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2335 (or 2322 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1921445568 is about 43834.2967093120. The cubic root of 1921445568 is about 1243.2048488454.

The spelling of 1921445568 in words is "one billion, nine hundred twenty-one million, four hundred forty-five thousand, five hundred sixty-eight".