3778681 has 2 divisors, whose sum is σ = 3778682. Its totient is φ = 3778680.

The previous prime is 3778679. The next prime is 3778717. The reversal of 3778681 is 1868773.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1915456 + 1863225 = 1384^2 + 1365^2 .

It is a cyclic number.

It is not a de Polignac number, because 3778681 - 2¹ = 3778679 is a prime.

It is a super-2 number, since 2×3778681² = 28556860199522, which contains 22 as substring.

Together with 3778679, it forms a pair of twin primes.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (3778651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1889340 + 1889341.

It is an arithmetic number, because the mean of its divisors is an integer number (1889341).

Almost surely, 2^3778681 is an apocalyptic number.

It is an amenable number.

3778681 is a deficient number, since it is larger than the sum of its proper divisors (1).

3778681 is an equidigital number, since it uses as much as digits as its factorization.

3778681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 40.

The square root of 3778681 is about 1943.8829697284. The cubic root of 3778681 is about 155.7567021653.

The spelling of 3778681 in words is "three million, seven hundred seventy-eight thousand, six hundred eighty-one".