6671821 has 8 divisors (see below), whose sum is σ = 7225344. Its totient is φ = 6124080.

The previous prime is 6671809. The next prime is 6671839. The reversal of 6671821 is 1281766.

6671821 = T₁₆₃ + T₁₆₄ + ... + T₃₅₃.

It is the 1055-th star number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6671821 - 2⁹ = 6671309 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 (6671801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1140 + ... + 3826.

It is an arithmetic number, because the mean of its divisors is an integer number (903168).

Almost surely, 2^6671821 is an apocalyptic number.

It is an amenable number.

6671821 is a deficient number, since it is larger than the sum of its proper divisors (553523).

6671821 is a wasteful number, since it uses less digits than its factorization.

6671821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2891.

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

The square root of 6671821 is about 2582.9868369777. The cubic root of 6671821 is about 188.2556974150.

The spelling of 6671821 in words is "six million, six hundred seventy-one thousand, eight hundred twenty-one".