6855421 has 4 divisors (see below), whose sum is σ = 6860700. Its totient is φ = 6850144.

The previous prime is 6855419. The next prime is 6855451. The reversal of 6855421 is 1245586.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1245586 = 2 ⋅622793.

It can be written as a sum of positive squares in 2 ways, for example, as 2280100 + 4575321 = 1510^2 + 2139^2 .

It is a cyclic number.

It is not a de Polignac number, because 6855421 - 2¹ = 6855419 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 (6855451) 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, 825 + ... + 3793.

It is an arithmetic number, because the mean of its divisors is an integer number (1715175).

Almost surely, 2^6855421 is an apocalyptic number.

It is an amenable number.

6855421 is a deficient number, since it is larger than the sum of its proper divisors (5279).

6855421 is a wasteful number, since it uses less digits than its factorization.

6855421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5278.

The product of its digits is 9600, while the sum is 31.

The square root of 6855421 is about 2618.2858896614. The cubic root of 6855421 is about 189.9669471590.

The spelling of 6855421 in words is "six million, eight hundred fifty-five thousand, four hundred twenty-one".