28304866661 has 2 divisors, whose sum is σ = 28304866662. Its totient is φ = 28304866660.

The previous prime is 28304866657. The next prime is 28304866679. The reversal of 28304866661 is 16666840382.

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., 21051108100 + 7253758561 = 145090^2 + 85169^2 .

It is a cyclic number.

It is not a de Polignac number, because 28304866661 - 2² = 28304866657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28304866861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14152433330 + 14152433331.

It is an arithmetic number, because the mean of its divisors is an integer number (14152433331).

Almost surely, 2^28304866661 is an apocalyptic number.

It is an amenable number.

28304866661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28304866661 is an equidigital number, since it uses as much as digits as its factorization.

28304866661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1990656, while the sum is 50.

The spelling of 28304866661 in words is "twenty-eight billion, three hundred four million, eight hundred sixty-six thousand, six hundred sixty-one".