6542600021 has 2 divisors, whose sum is σ = 6542600022. Its totient is φ = 6542600020.

The previous prime is 6542599997. The next prime is 6542600047. The reversal of 6542600021 is 1200062456.

It is an a-pointer prime, because the next prime (6542600047) can be obtained adding 6542600021 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4210192996 + 2332407025 = 64886^2 + 48295^2 .

It is a cyclic number.

It is not a de Polignac number, because 6542600021 - 2¹⁸ = 6542337877 is a prime.

It is a congruent number.

It is a weakly prime.

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, 3271300010 + 3271300011.

It is an arithmetic number, because the mean of its divisors is an integer number (3271300011).

Almost surely, 2^6542600021 is an apocalyptic number.

It is an amenable number.

6542600021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6542600021 is an equidigital number, since it uses as much as digits as its factorization.

6542600021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 6542600021 is about 80886.3401384931. The cubic root of 6542600021 is about 1870.3237565592.

Adding to 6542600021 its reverse (1200062456), we get a palindrome (7742662477).

The spelling of 6542600021 in words is "six billion, five hundred forty-two million, six hundred thousand, twenty-one".