3781691 has 2 divisors, whose sum is σ = 3781692. Its totient is φ = 3781690.

The previous prime is 3781669. The next prime is 3781711. The reversal of 3781691 is 1961873.

It is a strong prime.

It is an emirp because it is prime and its reverse (1961873) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3781691 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3784691) 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, 1890845 + 1890846.

It is an arithmetic number, because the mean of its divisors is an integer number (1890846).

Almost surely, 2^3781691 is an apocalyptic number.

3781691 is a deficient number, since it is larger than the sum of its proper divisors (1).

3781691 is an equidigital number, since it uses as much as digits as its factorization.

3781691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 3781691 is about 1944.6570391717. The cubic root of 3781691 is about 155.7980484484.

The spelling of 3781691 in words is "three million, seven hundred eighty-one thousand, six hundred ninety-one".