19729475491 has 8 divisors (see below), whose sum is σ = 21544971264. Its totient is φ = 17917630920.

The previous prime is 19729475449. The next prime is 19729475497. The reversal of 19729475491 is 19457492791.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19729475491 - 2²⁵ = 19695921059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19729475497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 901491 + ... + 923116.

It is an arithmetic number, because the mean of its divisors is an integer number (2693121408).

Almost surely, 2^19729475491 is an apocalyptic number.

19729475491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19729475491 is a deficient number, since it is larger than the sum of its proper divisors (1815495773).

19729475491 is a wasteful number, since it uses less digits than its factorization.

19729475491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1825601.

The product of its digits is 5715360, while the sum is 58.

The spelling of 19729475491 in words is "nineteen billion, seven hundred twenty-nine million, four hundred seventy-five thousand, four hundred ninety-one".