19909492181 has 2 divisors, whose sum is σ = 19909492182. Its totient is φ = 19909492180.

The previous prime is 19909492147. The next prime is 19909492243. The reversal of 19909492181 is 18129490991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16989819025 + 2919673156 = 130345^2 + 54034^2 .

It is a cyclic number.

It is not a de Polignac number, because 19909492181 - 2¹⁴ = 19909475797 is a prime.

It is a super-2 number, since 2×19909492181² (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 (19909432181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9954746090 + 9954746091.

It is an arithmetic number, because the mean of its divisors is an integer number (9954746091).

Almost surely, 2^19909492181 is an apocalyptic number.

It is an amenable number.

19909492181 is a deficient number, since it is larger than the sum of its proper divisors (1).

19909492181 is an equidigital number, since it uses as much as digits as its factorization.

19909492181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 53.

The spelling of 19909492181 in words is "nineteen billion, nine hundred nine million, four hundred ninety-two thousand, one hundred eighty-one".