6921613342421 has 2 divisors, whose sum is σ = 6921613342422. Its totient is φ = 6921613342420.

The previous prime is 6921613342411. The next prime is 6921613342429. The reversal of 6921613342421 is 1242433161296.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6846255406225 + 75357936196 = 2616535^2 + 274514^2 .

It is a cyclic number.

It is not a de Polignac number, because 6921613342421 - 2¹⁰ = 6921613341397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6921613342429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3460806671210 + 3460806671211.

It is an arithmetic number, because the mean of its divisors is an integer number (3460806671211).

Almost surely, 2^{6921613342421} is an apocalyptic number.

It is an amenable number.

6921613342421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6921613342421 is an equidigital number, since it uses as much as digits as its factorization.

6921613342421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 44.

The spelling of 6921613342421 in words is "six trillion, nine hundred twenty-one billion, six hundred thirteen million, three hundred forty-two thousand, four hundred twenty-one".