19444278491 has 12 divisors (see below), whose sum is σ = 21672887640. Its totient is φ = 17300496960.

The previous prime is 19444278481. The next prime is 19444278551. The reversal of 19444278491 is 19487244491.

It is not a de Polignac number, because 19444278491 - 2³⁴ = 2264409307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19444278401) 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 11 ways as a sum of consecutive naturals, for example, 375806 + ... + 424403.

It is an arithmetic number, because the mean of its divisors is an integer number (1806073970).

Almost surely, 2^19444278491 is an apocalyptic number.

19444278491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19444278491 is a deficient number, since it is larger than the sum of its proper divisors (2228609149).

19444278491 is an equidigital number, since it uses as much as digits as its factorization.

19444278491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800314 (or 800267 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 53.

The spelling of 19444278491 in words is "nineteen billion, four hundred forty-four million, two hundred seventy-eight thousand, four hundred ninety-one".