19689601 has 2 divisors, whose sum is σ = 19689602. Its totient is φ = 19689600.

The previous prime is 19689599. The next prime is 19689611. The reversal of 19689601 is 10698691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19149376 + 540225 = 4376^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 19689601 - 2¹ = 19689599 is a prime.

Together with 19689599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19689611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9844800 + 9844801.

It is an arithmetic number, because the mean of its divisors is an integer number (9844801).

Almost surely, 2^19689601 is an apocalyptic number.

It is an amenable number.

19689601 is a deficient number, since it is larger than the sum of its proper divisors (1).

19689601 is an equidigital number, since it uses as much as digits as its factorization.

19689601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 19689601 is about 4437.2965868871. The cubic root of 19689601 is about 270.0301795255.

The spelling of 19689601 in words is "nineteen million, six hundred eighty-nine thousand, six hundred one".