19506439691 has 2 divisors, whose sum is σ = 19506439692. Its totient is φ = 19506439690.

The previous prime is 19506439669. The next prime is 19506439709. The reversal of 19506439691 is 19693460591.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19506439691 - 2³⁴ = 2326570507 is a prime.

It is not a weakly prime, because it can be changed into another prime (19506439291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9753219845 + 9753219846.

It is an arithmetic number, because the mean of its divisors is an integer number (9753219846).

Almost surely, 2^19506439691 is an apocalyptic number.

19506439691 is a deficient number, since it is larger than the sum of its proper divisors (1).

19506439691 is an equidigital number, since it uses as much as digits as its factorization.

19506439691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1574640, while the sum is 53.

The spelling of 19506439691 in words is "nineteen billion, five hundred six million, four hundred thirty-nine thousand, six hundred ninety-one".