19691493841 has 4 divisors (see below), whose sum is σ = 20370510900. Its totient is φ = 19012476784.

The previous prime is 19691493799. The next prime is 19691493853. The reversal of 19691493841 is 14839419691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9944078400 + 9747415441 = 99720^2 + 98729^2 .

It is a cyclic number.

It is not a de Polignac number, because 19691493841 - 2²¹ = 19689396689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19691493541) 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 in 3 ways as a sum of consecutive naturals, for example, 339508486 + ... + 339508543.

It is an arithmetic number, because the mean of its divisors is an integer number (5092627725).

Almost surely, 2^19691493841 is an apocalyptic number.

It is an amenable number.

19691493841 is a deficient number, since it is larger than the sum of its proper divisors (679017059).

19691493841 is an equidigital number, since it uses as much as digits as its factorization.

19691493841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679017058.

The product of its digits is 1679616, while the sum is 55.

The spelling of 19691493841 in words is "nineteen billion, six hundred ninety-one million, four hundred ninety-three thousand, eight hundred forty-one".