19956679 has 2 divisors, whose sum is σ = 19956680. Its totient is φ = 19956678.

The previous prime is 19956659. The next prime is 19956697. The reversal of 19956679 is 97665991.

Together with next prime (19956697) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (97665991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19956679 - 2¹¹ = 19954631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19956659) 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, 9978339 + 9978340.

It is an arithmetic number, because the mean of its divisors is an integer number (9978340).

Almost surely, 2^19956679 is an apocalyptic number.

19956679 is a deficient number, since it is larger than the sum of its proper divisors (1).

19956679 is an equidigital number, since it uses as much as digits as its factorization.

19956679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 918540, while the sum is 52.

The square root of 19956679 is about 4467.2898943319. The cubic root of 19956679 is about 271.2456345082.

The spelling of 19956679 in words is "nineteen million, nine hundred fifty-six thousand, six hundred seventy-nine".