19819665011 has 4 divisors (see below), whose sum is σ = 19820101224. Its totient is φ = 19819228800.

The previous prime is 19819664989. The next prime is 19819665013. The reversal of 19819665011 is 11056691891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11056691891 = 7 ⋅1579527413.

It is a cyclic number.

It is not a de Polignac number, because 19819665011 - 2²² = 19815470707 is a prime.

It is a super-2 number, since 2×19819665011² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19819665013) 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, 140825 + ... + 243866.

It is an arithmetic number, because the mean of its divisors is an integer number (4955025306).

Almost surely, 2^19819665011 is an apocalyptic number.

19819665011 is a deficient number, since it is larger than the sum of its proper divisors (436213).

19819665011 is an equidigital number, since it uses as much as digits as its factorization.

19819665011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436212.

The product of its (nonzero) digits is 116640, while the sum is 47.

The spelling of 19819665011 in words is "nineteen billion, eight hundred nineteen million, six hundred sixty-five thousand, eleven".