3840721920 has 704 divisors, whose sum is σ = 16113984000. Its totient is φ = 877879296.

The previous prime is 3840721877. The next prime is 3840721939. The reversal of 3840721920 is 291270483.

3840721920 is a `hidden beast` number, since 38 + 407 + 219 + 2 + 0 = 666.

It is a super-2 number, since 2×3840721920² = 29502289733536972800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 548674557 + ... + 548674563.

Almost surely, 2^3840721920 is an apocalyptic number.

3840721920 is a gapful number since it is divisible by the number (30) 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 3840721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8056992000).

3840721920 is an abundant number, since it is smaller than the sum of its proper divisors (12273262080).

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

3840721920 is an frugal number, since it uses more digits than its factorization.

3840721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 3840721920 is about 61973.5582325237. The cubic root of 3840721920 is about 1566.0451830007.

The spelling of 3840721920 in words is "three billion, eight hundred forty million, seven hundred twenty-one thousand, nine hundred twenty".