78668563 has 2 divisors, whose sum is σ = 78668564. Its totient is φ = 78668562.

The previous prime is 78668509. The next prime is 78668591. The reversal of 78668563 is 36586687.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78668563 - 2¹⁷ = 78537491 is a prime.

It is not a weakly prime, because it can be changed into another prime (78668593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39334281 + 39334282.

It is an arithmetic number, because the mean of its divisors is an integer number (39334282).

Almost surely, 2^78668563 is an apocalyptic number.

78668563 is a deficient number, since it is larger than the sum of its proper divisors (1).

78668563 is an equidigital number, since it uses as much as digits as its factorization.

78668563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 49.

The square root of 78668563 is about 8869.5300326455. The cubic root of 78668563 is about 428.4831411206.

The spelling of 78668563 in words is "seventy-eight million, six hundred sixty-eight thousand, five hundred sixty-three".