19966679 has 2 divisors, whose sum is σ = 19966680. Its totient is φ = 19966678.

The previous prime is 19966657. The next prime is 19966699. The reversal of 19966679 is 97666991.

It is a strong prime.

It is an emirp because it is prime and its reverse (97666991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19966679 - 2⁸ = 19966423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19966679.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19966649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9983339 + 9983340.

It is an arithmetic number, because the mean of its divisors is an integer number (9983340).

Almost surely, 2^19966679 is an apocalyptic number.

19966679 is a deficient number, since it is larger than the sum of its proper divisors (1).

19966679 is an equidigital number, since it uses as much as digits as its factorization.

19966679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1102248, while the sum is 53.

The square root of 19966679 is about 4468.4090009756. The cubic root of 19966679 is about 271.2909326832.

The spelling of 19966679 in words is "nineteen million, nine hundred sixty-six thousand, six hundred seventy-nine".