3916021 has 2 divisors, whose sum is σ = 3916022. Its totient is φ = 3916020.

The previous prime is 3916019. The next prime is 3916027. The reversal of 3916021 is 1206193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2604996 + 1311025 = 1614^2 + 1145^2 .

It is a cyclic number.

It is not a de Polignac number, because 3916021 - 2¹ = 3916019 is a prime.

Together with 3916019, it forms a pair of twin primes.

3916021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3915983 and 3916001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3916027) 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, 1958010 + 1958011.

It is an arithmetic number, because the mean of its divisors is an integer number (1958011).

Almost surely, 2^3916021 is an apocalyptic number.

It is an amenable number.

3916021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3916021 is an equidigital number, since it uses as much as digits as its factorization.

3916021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 3916021 is about 1978.8938829558. The cubic root of 3916021 is about 157.6213359117.

The spelling of 3916021 in words is "three million, nine hundred sixteen thousand, twenty-one".