3781645 has 16 divisors (see below), whose sum is σ = 5241600. Its totient is φ = 2565504.

The previous prime is 3781643. The next prime is 3781649. The reversal of 3781645 is 5461873.

3781645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 3781645 - 2¹ = 3781643 is a prime.

It is a super-3 number, since 3×3781645³ (a number of 21 digits) contains 333 as substring.

3781645 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3781645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3781643) 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 in 15 ways as a sum of consecutive naturals, for example, 3081 + ... + 4129.

It is an arithmetic number, because the mean of its divisors is an integer number (327600).

Almost surely, 2^3781645 is an apocalyptic number.

3781645 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

3781645 is a deficient number, since it is larger than the sum of its proper divisors (1459955).

3781645 is a wasteful number, since it uses less digits than its factorization.

3781645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164.

The product of its digits is 20160, while the sum is 34.

The square root of 3781645 is about 1944.6452118574. The cubic root of 3781645 is about 155.7974167434.

The spelling of 3781645 in words is "three million, seven hundred eighty-one thousand, six hundred forty-five".