3985781 has 4 divisors (see below), whose sum is σ = 3999072. Its totient is φ = 3972492.

The previous prime is 3985777. The next prime is 3985829. The reversal of 3985781 is 1875893.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 3985781 - 2² = 3985777 is a prime.

It is a super-2 number, since 2×3985781² = 31772900359922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3985711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6185 + ... + 6798.

It is an arithmetic number, because the mean of its divisors is an integer number (999768).

Almost surely, 2^3985781 is an apocalyptic number.

It is an amenable number.

3985781 is a deficient number, since it is larger than the sum of its proper divisors (13291).

3985781 is a wasteful number, since it uses less digits than its factorization.

3985781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13290.

The product of its digits is 60480, while the sum is 41.

The square root of 3985781 is about 1996.4420853108. The cubic root of 3985781 is about 158.5517880838.

The spelling of 3985781 in words is "three million, nine hundred eighty-five thousand, seven hundred eighty-one".