3781649 has 2 divisors, whose sum is σ = 3781650. Its totient is φ = 3781648.

The previous prime is 3781643. The next prime is 3781663. The reversal of 3781649 is 9461873.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3775249 + 6400 = 1943^2 + 80^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3781649 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (3781643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1890824 + 1890825.

It is an arithmetic number, because the mean of its divisors is an integer number (1890825).

Almost surely, 2^3781649 is an apocalyptic number.

It is an amenable number.

3781649 is a deficient number, since it is larger than the sum of its proper divisors (1).

3781649 is an equidigital number, since it uses as much as digits as its factorization.

3781649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 38.

The square root of 3781649 is about 1944.6462403224. The cubic root of 3781649 is about 155.7974716745.

The spelling of 3781649 in words is "three million, seven hundred eighty-one thousand, six hundred forty-nine".