3935665421 has 2 divisors, whose sum is σ = 3935665422. Its totient is φ = 3935665420.

The previous prime is 3935665379. The next prime is 3935665423. The reversal of 3935665421 is 1245665393.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3710515396 + 225150025 = 60914^2 + 15005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3935665421 is a prime.

It is a Sophie Germain prime.

Together with 3935665423, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3935665423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1967832710 + 1967832711.

It is an arithmetic number, because the mean of its divisors is an integer number (1967832711).

Almost surely, 2^3935665421 is an apocalyptic number.

It is an amenable number.

3935665421 is a deficient number, since it is larger than the sum of its proper divisors (1).

3935665421 is an equidigital number, since it uses as much as digits as its factorization.

3935665421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 44.

The square root of 3935665421 is about 62734.8820115253. The cubic root of 3935665421 is about 1578.8446155870.

The spelling of 3935665421 in words is "three billion, nine hundred thirty-five million, six hundred sixty-five thousand, four hundred twenty-one".