19491920205 has 8 divisors (see below), whose sum is σ = 31187072352. Its totient is φ = 10395690768.

The previous prime is 19491920179. The next prime is 19491920213. The reversal of 19491920205 is 50202919491.

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

It is not a de Polignac number, because 19491920205 - 2¹² = 19491916109 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 649730659 + ... + 649730688.

It is an arithmetic number, because the mean of its divisors is an integer number (3898384044).

Almost surely, 2^19491920205 is an apocalyptic number.

19491920205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19491920205 is a deficient number, since it is larger than the sum of its proper divisors (11695152147).

19491920205 is a wasteful number, since it uses less digits than its factorization.

19491920205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299461355.

The product of its (nonzero) digits is 58320, while the sum is 42.

The spelling of 19491920205 in words is "nineteen billion, four hundred ninety-one million, nine hundred twenty thousand, two hundred five".