19664101 has 2 divisors, whose sum is σ = 19664102. Its totient is φ = 19664100.

The previous prime is 19664081. The next prime is 19664123. The reversal of 19664101 is 10146691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12773476 + 6890625 = 3574^2 + 2625^2 .

It is a cyclic number.

It is not a de Polignac number, because 19664101 - 2¹¹ = 19662053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19664101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19664171) 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, 9832050 + 9832051.

It is an arithmetic number, because the mean of its divisors is an integer number (9832051).

Almost surely, 2^19664101 is an apocalyptic number.

It is an amenable number.

19664101 is a deficient number, since it is larger than the sum of its proper divisors (1).

19664101 is an equidigital number, since it uses as much as digits as its factorization.

19664101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 19664101 is about 4434.4222848078. The cubic root of 19664101 is about 269.9135571469.

The spelling of 19664101 in words is "nineteen million, six hundred sixty-four thousand, one hundred one".