6542041621 has 2 divisors, whose sum is σ = 6542041622. Its totient is φ = 6542041620.

The previous prime is 6542041607. The next prime is 6542041699. The reversal of 6542041621 is 1261402456.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4735366596 + 1806675025 = 68814^2 + 42505^2 .

It is a cyclic number.

It is not a de Polignac number, because 6542041621 - 2¹¹ = 6542039573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6542041021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3271020810 + 3271020811.

It is an arithmetic number, because the mean of its divisors is an integer number (3271020811).

Almost surely, 2^6542041621 is an apocalyptic number.

It is an amenable number.

6542041621 is a deficient number, since it is larger than the sum of its proper divisors (1).

6542041621 is an equidigital number, since it uses as much as digits as its factorization.

6542041621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 6542041621 is about 80882.8883077255. Note that the first 3 decimals coincide. The cubic root of 6542041621 is about 1870.2705453742.

The spelling of 6542041621 in words is "six billion, five hundred forty-two million, forty-one thousand, six hundred twenty-one".