3981311961 has 16 divisors (see below), whose sum is σ = 5845125888. Its totient is φ = 2390363600.

The previous prime is 3981311933. The next prime is 3981311987. The reversal of 3981311961 is 1691131893.

It is a cyclic number.

It is not a de Polignac number, because 3981311961 - 2⁷ = 3981311833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3981311921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 560235 + ... + 567296.

It is an arithmetic number, because the mean of its divisors is an integer number (365320368).

Almost surely, 2^3981311961 is an apocalyptic number.

It is an amenable number.

3981311961 is a deficient number, since it is larger than the sum of its proper divisors (1863813927).

3981311961 is a wasteful number, since it uses less digits than its factorization.

3981311961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127652.

The product of its digits is 34992, while the sum is 42.

The square root of 3981311961 is about 63097.6383155503. The cubic root of 3981311961 is about 1584.9250742942.

The spelling of 3981311961 in words is "three billion, nine hundred eighty-one million, three hundred eleven thousand, nine hundred sixty-one".