19619845381 has 2 divisors, whose sum is σ = 19619845382. Its totient is φ = 19619845380.

The previous prime is 19619845351. The next prime is 19619845481. The reversal of 19619845381 is 18354891691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10796249025 + 8823596356 = 103905^2 + 93934^2 .

It is an emirp because it is prime and its reverse (18354891691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19619845381 - 2⁹ = 19619844869 is a prime.

It is a super-2 number, since 2×19619845381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19619845331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9809922690 + 9809922691.

It is an arithmetic number, because the mean of its divisors is an integer number (9809922691).

Almost surely, 2^19619845381 is an apocalyptic number.

It is an amenable number.

19619845381 is a deficient number, since it is larger than the sum of its proper divisors (1).

19619845381 is an equidigital number, since it uses as much as digits as its factorization.

19619845381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1866240, while the sum is 55.

The spelling of 19619845381 in words is "nineteen billion, six hundred nineteen million, eight hundred forty-five thousand, three hundred eighty-one".