3963721 has 2 divisors, whose sum is σ = 3963722. Its totient is φ = 3963720.

The previous prime is 3963709. The next prime is 3963763. The reversal of 3963721 is 1273693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2673225 + 1290496 = 1635^2 + 1136^2 .

It is an emirp because it is prime and its reverse (1273693) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3963721 - 2⁹ = 3963209 is a prime.

It is a super-2 number, since 2×3963721² = 31422168331682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3963121) 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 as a sum of consecutive naturals, namely, 1981860 + 1981861.

It is an arithmetic number, because the mean of its divisors is an integer number (1981861).

Almost surely, 2^3963721 is an apocalyptic number.

It is an amenable number.

3963721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3963721 is an equidigital number, since it uses as much as digits as its factorization.

3963721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 31.

The square root of 3963721 is about 1990.9095911166. The cubic root of 3963721 is about 158.2587359276.

The spelling of 3963721 in words is "three million, nine hundred sixty-three thousand, seven hundred twenty-one".