3888781 has 4 divisors (see below), whose sum is σ = 4187932. Its totient is φ = 3589632.

The previous prime is 3888763. The next prime is 3888823. The reversal of 3888781 is 1878883.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 826281 + 3062500 = 909^2 + 1750^2 .

It is a cyclic number.

It is not a de Polignac number, because 3888781 - 2⁷ = 3888653 is a prime.

It is a super-2 number, since 2×3888781² = 30245235331922, which contains 22 as substring.

It is a Duffinian number.

3888781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3888721) 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, 149556 + ... + 149581.

It is an arithmetic number, because the mean of its divisors is an integer number (1046983).

Almost surely, 2^3888781 is an apocalyptic number.

It is an amenable number.

3888781 is a deficient number, since it is larger than the sum of its proper divisors (299151).

3888781 is a wasteful number, since it uses less digits than its factorization.

3888781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299150.

The product of its digits is 86016, while the sum is 43.

The square root of 3888781 is about 1971.9992393508. Note that the first 3 decimals coincide. The cubic root of 3888781 is about 157.2550117492.

The spelling of 3888781 in words is "three million, eight hundred eighty-eight thousand, seven hundred eighty-one".