6661220756459 has 2 divisors, whose sum is σ = 6661220756460. Its totient is φ = 6661220756458.

The previous prime is 6661220756453. The next prime is 6661220756569. The reversal of 6661220756459 is 9546570221666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6661220756459 - 2²⁸ = 6660952321003 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6661220756398 and 6661220756407.

It is not a weakly prime, because it can be changed into another prime (6661220756453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330610378229 + 3330610378230.

It is an arithmetic number, because the mean of its divisors is an integer number (3330610378230).

Almost surely, 2^{6661220756459} is an apocalyptic number.

6661220756459 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661220756459 is an equidigital number, since it uses as much as digits as its factorization.

6661220756459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32659200, while the sum is 59.

The spelling of 6661220756459 in words is "six trillion, six hundred sixty-one billion, two hundred twenty million, seven hundred fifty-six thousand, four hundred fifty-nine".