19455505491 has 4 divisors (see below), whose sum is σ = 25940673992. Its totient is φ = 12970336992.

The previous prime is 19455505463. The next prime is 19455505507. The reversal of 19455505491 is 19450555491.

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

It is not a de Polignac number, because 19455505491 - 2⁹ = 19455504979 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 19455505491.

It is not an unprimeable number, because it can be changed into a prime (19455504491) 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, 3242584246 + ... + 3242584251.

It is an arithmetic number, because the mean of its divisors is an integer number (6485168498).

Almost surely, 2^19455505491 is an apocalyptic number.

19455505491 is a deficient number, since it is larger than the sum of its proper divisors (6485168501).

19455505491 is an equidigital number, since it uses as much as digits as its factorization.

19455505491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6485168500.

The product of its (nonzero) digits is 810000, while the sum is 48.

The spelling of 19455505491 in words is "nineteen billion, four hundred fifty-five million, five hundred five thousand, four hundred ninety-one".