6671620021 has 8 divisors (see below), whose sum is σ = 7281958464. Its totient is φ = 6061919520.

The previous prime is 6671620013. The next prime is 6671620091. The reversal of 6671620021 is 1200261766.

It is a happy 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 6671620021 - 2³ = 6671620013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6671620091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137481 + ... + 179566.

It is an arithmetic number, because the mean of its divisors is an integer number (910244808).

Almost surely, 2^6671620021 is an apocalyptic number.

It is an amenable number.

6671620021 is a deficient number, since it is larger than the sum of its proper divisors (610338443).

6671620021 is a wasteful number, since it uses less digits than its factorization.

6671620021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318971.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 6671620021 is about 81679.9854370702. The cubic root of 6671620021 is about 1882.5380708539.

Adding to 6671620021 its reverse (1200261766), we get a palindrome (7871881787).

The spelling of 6671620021 in words is "six billion, six hundred seventy-one million, six hundred twenty thousand, twenty-one".