6921917 has 2 divisors, whose sum is σ = 6921918. Its totient is φ = 6921916.

The previous prime is 6921883. The next prime is 6921949. The reversal of 6921917 is 7191296.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6584356 + 337561 = 2566^2 + 581^2 .

It is a cyclic number.

It is not a de Polignac number, because 6921917 - 2¹² = 6917821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6921017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3460958 + 3460959.

It is an arithmetic number, because the mean of its divisors is an integer number (3460959).

Almost surely, 2^6921917 is an apocalyptic number.

It is an amenable number.

6921917 is a deficient number, since it is larger than the sum of its proper divisors (1).

6921917 is an equidigital number, since it uses as much as digits as its factorization.

6921917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 35.

The square root of 6921917 is about 2630.9536293899. The cubic root of 6921917 is about 190.5791837216.

The spelling of 6921917 in words is "six million, nine hundred twenty-one thousand, nine hundred seventeen".