19619819641 has 2 divisors, whose sum is σ = 19619819642. Its totient is φ = 19619819640.

The previous prime is 19619819591. The next prime is 19619819671. The reversal of 19619819641 is 14691891691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17061584400 + 2558235241 = 130620^2 + 50579^2 .

It is a cyclic number.

It is not a de Polignac number, because 19619819641 - 2²⁷ = 19485601913 is a prime.

It is not a weakly prime, because it can be changed into another prime (19619819671) 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, 9809909820 + 9809909821.

It is an arithmetic number, because the mean of its divisors is an integer number (9809909821).

Almost surely, 2^19619819641 is an apocalyptic number.

It is an amenable number.

19619819641 is a deficient number, since it is larger than the sum of its proper divisors (1).

19619819641 is an equidigital number, since it uses as much as digits as its factorization.

19619819641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 55.

The spelling of 19619819641 in words is "nineteen billion, six hundred nineteen million, eight hundred nineteen thousand, six hundred forty-one".