3966021841 has 4 divisors (see below), whose sum is σ = 3966153652. Its totient is φ = 3965890032.

The previous prime is 3966021803. The next prime is 3966021847. The reversal of 3966021841 is 1481206693.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1092633025 + 2873388816 = 33055^2 + 53604^2 .

It is a cyclic number.

It is not a de Polignac number, because 3966021841 - 2⁹ = 3966021329 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3966021794 and 3966021803.

It is not an unprimeable number, because it can be changed into a prime (3966021847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3811 + ... + 89143.

It is an arithmetic number, because the mean of its divisors is an integer number (991538413).

Almost surely, 2^3966021841 is an apocalyptic number.

It is an amenable number.

3966021841 is a deficient number, since it is larger than the sum of its proper divisors (131811).

3966021841 is an equidigital number, since it uses as much as digits as its factorization.

3966021841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131810.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 3966021841 is about 62976.3593819141. The cubic root of 3966021841 is about 1582.8935175174.

The spelling of 3966021841 in words is "three billion, nine hundred sixty-six million, twenty-one thousand, eight hundred forty-one".