19679697691 has 4 divisors (see below), whose sum is σ = 19680130152. Its totient is φ = 19679265232.

The previous prime is 19679697683. The next prime is 19679697757.

19679697691 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is not a de Polignac number, because 19679697691 - 2³ = 19679697683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19679697691.

It is not an unprimeable number, because it can be changed into a prime (19679697671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138706 + ... + 242071.

It is an arithmetic number, because the mean of its divisors is an integer number (4920032538).

Almost surely, 2^19679697691 is an apocalyptic number.

19679697691 is a deficient number, since it is larger than the sum of its proper divisors (432461).

19679697691 is an equidigital number, since it uses as much as digits as its factorization.

19679697691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432460.

The product of its digits is 69441624, while the sum is 70.

The spelling of 19679697691 in words is "nineteen billion, six hundred seventy-nine million, six hundred ninety-seven thousand, six hundred ninety-one".