19687828691 has 2 divisors, whose sum is σ = 19687828692. Its totient is φ = 19687828690.

The previous prime is 19687828603. The next prime is 19687828703. The reversal of 19687828691 is 19682878691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19687828691 - 2¹⁰ = 19687827667 is a prime.

It is a super-2 number, since 2×19687828691² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19687828591) 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, 9843914345 + 9843914346.

It is an arithmetic number, because the mean of its divisors is an integer number (9843914346).

Almost surely, 2^19687828691 is an apocalyptic number.

19687828691 is a deficient number, since it is larger than the sum of its proper divisors (1).

19687828691 is an equidigital number, since it uses as much as digits as its factorization.

19687828691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20901888, while the sum is 65.

The spelling of 19687828691 in words is "nineteen billion, six hundred eighty-seven million, eight hundred twenty-eight thousand, six hundred ninety-one".