6871621 has 4 divisors (see below), whose sum is σ = 7275852. Its totient is φ = 6467392.

The previous prime is 6871583. The next prime is 6871639. The reversal of 6871621 is 1261786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1261786 = 2 ⋅630893.

It can be written as a sum of positive squares in 2 ways, for example, as 1920996 + 4950625 = 1386^2 + 2225^2 .

It is a cyclic number.

It is not a de Polignac number, because 6871621 - 2¹¹ = 6869573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6871651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202090 + ... + 202123.

It is an arithmetic number, because the mean of its divisors is an integer number (1818963).

Almost surely, 2^6871621 is an apocalyptic number.

It is an amenable number.

6871621 is a deficient number, since it is larger than the sum of its proper divisors (404231).

6871621 is a wasteful number, since it uses less digits than its factorization.

6871621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404230.

The product of its digits is 4032, while the sum is 31.

The square root of 6871621 is about 2621.3776912151. The cubic root of 6871621 is about 190.1164659903.

The spelling of 6871621 in words is "six million, eight hundred seventy-one thousand, six hundred twenty-one".