6942215821 has 2 divisors, whose sum is σ = 6942215822. Its totient is φ = 6942215820.

The previous prime is 6942215767. The next prime is 6942215849. The reversal of 6942215821 is 1285122496.

It is a happy number.

6942215821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4005117796 + 2937098025 = 63286^2 + 54195^2 .

It is a cyclic number.

It is not a de Polignac number, because 6942215821 - 2⁹ = 6942215309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6942215881) 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 as a sum of consecutive naturals, namely, 3471107910 + 3471107911.

It is an arithmetic number, because the mean of its divisors is an integer number (3471107911).

Almost surely, 2^6942215821 is an apocalyptic number.

It is an amenable number.

6942215821 is a deficient number, since it is larger than the sum of its proper divisors (1).

6942215821 is an equidigital number, since it uses as much as digits as its factorization.

6942215821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 40.

The square root of 6942215821 is about 83319.9605196738. The cubic root of 6942215821 is about 1907.6529581261.

The spelling of 6942215821 in words is "six billion, nine hundred forty-two million, two hundred fifteen thousand, eight hundred twenty-one".