3981706321 has 4 divisors (see below), whose sum is σ = 3981918772. Its totient is φ = 3981493872.

The previous prime is 3981706283. The next prime is 3981706331. The reversal of 3981706321 is 1236071893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3492810000 + 488896321 = 59100^2 + 22111^2 .

It is a cyclic number.

It is not a de Polignac number, because 3981706321 - 2²³ = 3973317713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3981706331) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 75066 + ... + 116611.

It is an arithmetic number, because the mean of its divisors is an integer number (995479693).

Almost surely, 2^3981706321 is an apocalyptic number.

It is an amenable number.

3981706321 is a deficient number, since it is larger than the sum of its proper divisors (212451).

3981706321 is a wasteful number, since it uses less digits than its factorization.

3981706321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212450.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 3981706321 is about 63100.7632362716. The cubic root of 3981706321 is about 1584.9774029757.

The spelling of 3981706321 in words is "three billion, nine hundred eighty-one million, seven hundred six thousand, three hundred twenty-one".