3987281 has 4 divisors (see below), whose sum is σ = 3995712. Its totient is φ = 3978852.

The previous prime is 3987271. The next prime is 3987287. The reversal of 3987281 is 1827893.

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: 1827893 = 211 ⋅8663.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3987281 is a prime.

It is a super-2 number, since 2×3987281² = 31796819545922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3987287) 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, 3461 + ... + 4466.

It is an arithmetic number, because the mean of its divisors is an integer number (998928).

Almost surely, 2^3987281 is an apocalyptic number.

It is an amenable number.

3987281 is a deficient number, since it is larger than the sum of its proper divisors (8431).

3987281 is an equidigital number, since it uses as much as digits as its factorization.

3987281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8430.

The product of its digits is 24192, while the sum is 38.

The square root of 3987281 is about 1996.8177182707. The cubic root of 3987281 is about 158.5716752656.

The spelling of 3987281 in words is "three million, nine hundred eighty-seven thousand, two hundred eighty-one".