1921107664 has 80 divisors (see below), whose sum is σ = 4324294656. Its totient is φ = 809827200.

The previous prime is 1921107659. The next prime is 1921107679. The reversal of 1921107664 is 4667011291.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1862829 + ... + 1863859.

Almost surely, 2^1921107664 is an apocalyptic number.

1921107664 is a gapful number since it is divisible by the number (14) 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 1921107664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2162147328).

1921107664 is an abundant number, since it is smaller than the sum of its proper divisors (2403186992).

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

1921107664 is a wasteful number, since it uses less digits than its factorization.

1921107664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1304 (or 1298 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 1921107664 is about 43830.4422063022. The cubic root of 1921107664 is about 1243.1319682105.

The spelling of 1921107664 in words is "one billion, nine hundred twenty-one million, one hundred seven thousand, six hundred sixty-four".