3840721940 has 96 divisors (see below), whose sum is σ = 9806832000. Its totient is φ = 1245265920.

The previous prime is 3840721939. The next prime is 3840721943. The reversal of 3840721940 is 491270483.

It is a super-2 number, since 2×3840721940² = 29502290040794727200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 3840721894 and 3840721903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3840721943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44036 + ... + 98084.

It is an arithmetic number, because the mean of its divisors is an integer number (102154500).

Almost surely, 2^3840721940 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 3840721940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4903416000).

3840721940 is an abundant number, since it is smaller than the sum of its proper divisors (5966110060).

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

3840721940 is a wasteful number, since it uses less digits than its factorization.

3840721940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54105 (or 54103 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 3840721940 is about 61973.5583938828. The cubic root of 3840721940 is about 1566.0451857191.

The spelling of 3840721940 in words is "three billion, eight hundred forty million, seven hundred twenty-one thousand, nine hundred forty".