3891687 has 4 divisors (see below), whose sum is σ = 5188920. Its totient is φ = 2594456.

The previous prime is 3891683. The next prime is 3891689. The reversal of 3891687 is 7861983.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7861983 = 3 ⋅2620661.

It is a cyclic number.

It is not a de Polignac number, because 3891687 - 2² = 3891683 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3891683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 648612 + ... + 648617.

It is an arithmetic number, because the mean of its divisors is an integer number (1297230).

Almost surely, 2^3891687 is an apocalyptic number.

3891687 is a deficient number, since it is larger than the sum of its proper divisors (1297233).

3891687 is a wasteful number, since it uses less digits than its factorization.

3891687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297232.

The product of its digits is 72576, while the sum is 42.

The square root of 3891687 is about 1972.7359174507. The cubic root of 3891687 is about 157.2941730597.

The spelling of 3891687 in words is "three million, eight hundred ninety-one thousand, six hundred eighty-seven".