6543621551 has 2 divisors, whose sum is σ = 6543621552. Its totient is φ = 6543621550.

The previous prime is 6543621503. The next prime is 6543621563. The reversal of 6543621551 is 1551263456.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6543621551 - 2¹⁰ = 6543620527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6543621251) 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, 3271810775 + 3271810776.

It is an arithmetic number, because the mean of its divisors is an integer number (3271810776).

Almost surely, 2^6543621551 is an apocalyptic number.

6543621551 is a deficient number, since it is larger than the sum of its proper divisors (1).

6543621551 is an equidigital number, since it uses as much as digits as its factorization.

6543621551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108000, while the sum is 38.

The square root of 6543621551 is about 80892.6544934705. The cubic root of 6543621551 is about 1870.4210926026.

The spelling of 6543621551 in words is "six billion, five hundred forty-three million, six hundred twenty-one thousand, five hundred fifty-one".