19661241601 has 2 divisors, whose sum is σ = 19661241602. Its totient is φ = 19661241600.

The previous prime is 19661241571. The next prime is 19661241671. The reversal of 19661241601 is 10614216691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14611007376 + 5050234225 = 120876^2 + 71065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19661241601 is a prime.

It is not a weakly prime, because it can be changed into another prime (19661241671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9830620800 + 9830620801.

It is an arithmetic number, because the mean of its divisors is an integer number (9830620801).

Almost surely, 2^19661241601 is an apocalyptic number.

It is an amenable number.

19661241601 is a deficient number, since it is larger than the sum of its proper divisors (1).

19661241601 is an equidigital number, since it uses as much as digits as its factorization.

19661241601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 19661241601 in words is "nineteen billion, six hundred sixty-one million, two hundred forty-one thousand, six hundred one".