19919568901 has 4 divisors (see below), whose sum is σ = 19962592192. Its totient is φ = 19876545612.

The previous prime is 19919568869. The next prime is 19919568931. The reversal of 19919568901 is 10986591991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19919568901 - 2⁵ = 19919568869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19919568931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21510951 + ... + 21511876.

It is an arithmetic number, because the mean of its divisors is an integer number (4990648048).

Almost surely, 2^19919568901 is an apocalyptic number.

It is an amenable number.

19919568901 is a deficient number, since it is larger than the sum of its proper divisors (43023291).

19919568901 is an equidigital number, since it uses as much as digits as its factorization.

19919568901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43023290.

The product of its (nonzero) digits is 1574640, while the sum is 58.

The spelling of 19919568901 in words is "nineteen billion, nine hundred nineteen million, five hundred sixty-eight thousand, nine hundred one".