3925781 has 2 divisors, whose sum is σ = 3925782. Its totient is φ = 3925780.

The previous prime is 3925751. The next prime is 3925783. The reversal of 3925781 is 1875293.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2146225 + 1779556 = 1465^2 + 1334^2 .

It is a cyclic number.

It is not a de Polignac number, because 3925781 - 2⁶ = 3925717 is a prime.

It is a super-2 number, since 2×3925781² = 30823512919922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 3925783, 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 (3925783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1962890 + 1962891.

It is an arithmetic number, because the mean of its divisors is an integer number (1962891).

Almost surely, 2^3925781 is an apocalyptic number.

It is an amenable number.

3925781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3925781 is an equidigital number, since it uses as much as digits as its factorization.

3925781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 35.

The square root of 3925781 is about 1981.3583724304. The cubic root of 3925781 is about 157.7521751789.

The spelling of 3925781 in words is "three million, nine hundred twenty-five thousand, seven hundred eighty-one".