3897865 has 4 divisors (see below), whose sum is σ = 4677444. Its totient is φ = 3118288.

The previous prime is 3897853. The next prime is 3897871. The reversal of 3897865 is 5687983.

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 725904 + 3171961 = 852^2 + 1781^2 .

It is a cyclic number.

It is not a de Polignac number, because 3897865 - 2⁹ = 3897353 is a prime.

It is a Duffinian number.

3897865 is a lucky 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, 389782 + ... + 389791.

It is an arithmetic number, because the mean of its divisors is an integer number (1169361).

Almost surely, 2^3897865 is an apocalyptic number.

It is an amenable number.

3897865 is a deficient number, since it is larger than the sum of its proper divisors (779579).

3897865 is an equidigital number, since it uses as much as digits as its factorization.

3897865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779578.

The product of its digits is 362880, while the sum is 46.

The square root of 3897865 is about 1974.3011421766. The cubic root of 3897865 is about 157.3773631718.

It can be divided in two parts, 38 and 97865, that added together give a triangular number (97903 = T₄₄₂).

The spelling of 3897865 in words is "three million, eight hundred ninety-seven thousand, eight hundred sixty-five".