19665013 has 2 divisors, whose sum is σ = 19665014. Its totient is φ = 19665012.

The previous prime is 19665007. The next prime is 19665043. The reversal of 19665013 is 31056691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11410884 + 8254129 = 3378^2 + 2873^2 .

It is a cyclic number.

It is not a de Polignac number, because 19665013 - 2²¹ = 17567861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19665043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9832506 + 9832507.

It is an arithmetic number, because the mean of its divisors is an integer number (9832507).

Almost surely, 2^19665013 is an apocalyptic number.

It is an amenable number.

19665013 is a deficient number, since it is larger than the sum of its proper divisors (1).

19665013 is an equidigital number, since it uses as much as digits as its factorization.

19665013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 19665013 is about 4434.5251155000. The cubic root of 19665013 is about 269.9177298499.

The spelling of 19665013 in words is "nineteen million, six hundred sixty-five thousand, thirteen".