3786781 has 2 divisors, whose sum is σ = 3786782. Its totient is φ = 3786780.

The previous prime is 3786779. The next prime is 3786803. The reversal of 3786781 is 1876873.

3786781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2992900 + 793881 = 1730^2 + 891^2 .

It is a cyclic number.

It is not a de Polignac number, because 3786781 - 2¹ = 3786779 is a prime.

It is a super-2 number, since 2×3786781² = 28679420683922, which contains 22 as substring.

Together with 3786779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3786751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1893390 + 1893391.

It is an arithmetic number, because the mean of its divisors is an integer number (1893391).

Almost surely, 2^3786781 is an apocalyptic number.

It is an amenable number.

3786781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3786781 is an equidigital number, since it uses as much as digits as its factorization.

3786781 is an odious number, because the sum of its binary digits is odd.

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

The square root of 3786781 is about 1945.9653131544. The cubic root of 3786781 is about 155.8679163590.

The spelling of 3786781 in words is "three million, seven hundred eighty-six thousand, seven hundred eighty-one".