6671921 has 2 divisors, whose sum is σ = 6671922. Its totient is φ = 6671920.

The previous prime is 6671893. The next prime is 6671947. The reversal of 6671921 is 1291766.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6071296 + 600625 = 2464^2 + 775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6671921 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6677921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3335960 + 3335961.

It is an arithmetic number, because the mean of its divisors is an integer number (3335961).

Almost surely, 2^6671921 is an apocalyptic number.

It is an amenable number.

6671921 is a deficient number, since it is larger than the sum of its proper divisors (1).

6671921 is an equidigital number, since it uses as much as digits as its factorization.

6671921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 32.

The square root of 6671921 is about 2583.0061943402. The cubic root of 6671921 is about 188.2566379616.

Subtracting from 6671921 its sum of digits (32), we obtain a square (6671889 = 2583²).

The spelling of 6671921 in words is "six million, six hundred seventy-one thousand, nine hundred twenty-one".