19664479 has 2 divisors, whose sum is σ = 19664480. Its totient is φ = 19664478.

The previous prime is 19664467. The next prime is 19664497. The reversal of 19664479 is 97446691.

Together with next prime (19664497) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19664479 - 2⁹ = 19663967 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19664429) 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, 9832239 + 9832240.

It is an arithmetic number, because the mean of its divisors is an integer number (9832240).

Almost surely, 2^19664479 is an apocalyptic number.

19664479 is a deficient number, since it is larger than the sum of its proper divisors (1).

19664479 is an equidigital number, since it uses as much as digits as its factorization.

19664479 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 46.

The square root of 19664479 is about 4434.4649057130. The cubic root of 19664479 is about 269.9152866381.

The spelling of 19664479 in words is "nineteen million, six hundred sixty-four thousand, four hundred seventy-nine".