3988865 has 4 divisors (see below), whose sum is σ = 4786644. Its totient is φ = 3191088.

The previous prime is 3988823. The next prime is 3988877. The reversal of 3988865 is 5688893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5688893 = 7 ⋅812699.

It can be written as a sum of positive squares in 2 ways, for example, as 3125824 + 863041 = 1768^2 + 929^2 .

It is a cyclic number.

It is not a de Polignac number, because 3988865 - 2¹² = 3984769 is a prime.

It is a super-2 number, since 2×3988865² = 31822087976450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 398882 + ... + 398891.

It is an arithmetic number, because the mean of its divisors is an integer number (1196661).

Almost surely, 2^3988865 is an apocalyptic number.

It is an amenable number.

3988865 is a deficient number, since it is larger than the sum of its proper divisors (797779).

3988865 is an equidigital number, since it uses as much as digits as its factorization.

3988865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797778.

The product of its digits is 414720, while the sum is 47.

The square root of 3988865 is about 1997.2143099828. The cubic root of 3988865 is about 158.5926707159.

The spelling of 3988865 in words is "three million, nine hundred eighty-eight thousand, eight hundred sixty-five".