6451356661 has 2 divisors, whose sum is σ = 6451356662. Its totient is φ = 6451356660.

The previous prime is 6451356647. The next prime is 6451356689. The reversal of 6451356661 is 1666531546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5283836100 + 1167520561 = 72690^2 + 34169^2 .

It is a cyclic number.

It is not a de Polignac number, because 6451356661 - 2⁷ = 6451356533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6451356761) 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, 3225678330 + 3225678331.

It is an arithmetic number, because the mean of its divisors is an integer number (3225678331).

Almost surely, 2^6451356661 is an apocalyptic number.

It is an amenable number.

6451356661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6451356661 is an equidigital number, since it uses as much as digits as its factorization.

6451356661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388800, while the sum is 43.

The square root of 6451356661 is about 80320.3377794192. The cubic root of 6451356661 is about 1861.5884858605.

The spelling of 6451356661 in words is "six billion, four hundred fifty-one million, three hundred fifty-six thousand, six hundred sixty-one".