19049799781 has 2 divisors, whose sum is σ = 19049799782. Its totient is φ = 19049799780.

The previous prime is 19049799773. The next prime is 19049799829. The reversal of 19049799781 is 18799794091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10647144225 + 8402655556 = 103185^2 + 91666^2 .

It is a cyclic number.

It is not a de Polignac number, because 19049799781 - 2³ = 19049799773 is a prime.

It is a super-2 number, since 2×19049799781² (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 (19049799281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9524899890 + 9524899891.

It is an arithmetic number, because the mean of its divisors is an integer number (9524899891).

Almost surely, 2^19049799781 is an apocalyptic number.

It is an amenable number.

19049799781 is a deficient number, since it is larger than the sum of its proper divisors (1).

19049799781 is an equidigital number, since it uses as much as digits as its factorization.

19049799781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10287648, while the sum is 64.

The spelling of 19049799781 in words is "nineteen billion, forty-nine million, seven hundred ninety-nine thousand, seven hundred eighty-one".