3981581940 has 48 divisors (see below), whose sum is σ = 12741063552. Its totient is φ = 910075776.

The previous prime is 3981581921. The next prime is 3981581963. The reversal of 3981581940 is 491851893.

It is a self number, because there is not a number n which added to its sum of digits gives 3981581940.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4739559 + ... + 4740398.

It is an arithmetic number, because the mean of its divisors is an integer number (265438824).

Almost surely, 2^3981581940 is an apocalyptic number.

3981581940 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3981581940 is an abundant number, since it is smaller than the sum of its proper divisors (8759481612).

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

3981581940 is a wasteful number, since it uses less digits than its factorization.

3981581940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9479976 (or 9479974 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 48.

The square root of 3981581940 is about 63099.7776541249. Note that the first 3 decimals coincide. The cubic root of 3981581940 is about 1584.9608989017.

The spelling of 3981581940 in words is "three billion, nine hundred eighty-one million, five hundred eighty-one thousand, nine hundred forty".