3965781 has 4 divisors (see below), whose sum is σ = 5287712. Its totient is φ = 2643852.

The previous prime is 3965723. The next prime is 3965783. The reversal of 3965781 is 1875693.

3965781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1875693 = 3 ⋅625231.

It is not a de Polignac number, because 3965781 - 2⁷ = 3965653 is a prime.

It is a super-2 number, since 2×3965781² = 31454837879922, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3965783) 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 3 ways as a sum of consecutive naturals, for example, 660961 + ... + 660966.

It is an arithmetic number, because the mean of its divisors is an integer number (1321928).

Almost surely, 2^3965781 is an apocalyptic number.

It is an amenable number.

3965781 is a deficient number, since it is larger than the sum of its proper divisors (1321931).

3965781 is a wasteful number, since it uses less digits than its factorization.

3965781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1321930.

The product of its digits is 45360, while the sum is 39.

The square root of 3965781 is about 1991.4268753836. The cubic root of 3965781 is about 158.2861475891.

The spelling of 3965781 in words is "three million, nine hundred sixty-five thousand, seven hundred eighty-one".