3987881 has 4 divisors (see below), whose sum is σ = 3992064. Its totient is φ = 3983700.

The previous prime is 3987859. The next prime is 3987887. The reversal of 3987881 is 1887893.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3987881 is a prime.

It is a super-2 number, since 2×3987881² = 31806389740322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3987887) 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, 116 + ... + 2826.

It is an arithmetic number, because the mean of its divisors is an integer number (998016).

Almost surely, 2^3987881 is an apocalyptic number.

It is an amenable number.

3987881 is a deficient number, since it is larger than the sum of its proper divisors (4183).

3987881 is a wasteful number, since it uses less digits than its factorization.

3987881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4182.

The product of its digits is 96768, while the sum is 44.

The square root of 3987881 is about 1996.9679516707. The cubic root of 3987881 is about 158.5796287418.

The spelling of 3987881 in words is "three million, nine hundred eighty-seven thousand, eight hundred eighty-one".