19519928605 has 4 divisors (see below), whose sum is σ = 23423914332. Its totient is φ = 15615942880.

The previous prime is 19519928587. The next prime is 19519928621. The reversal of 19519928605 is 50682991591.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14222709081 + 5297219524 = 119259^2 + 72782^2 .

It is not a de Polignac number, because 19519928605 - 2¹⁷ = 19519797533 is a prime.

It is a super-2 number, since 2×19519928605² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1951992856 + ... + 1951992865.

It is an arithmetic number, because the mean of its divisors is an integer number (5855978583).

Almost surely, 2^19519928605 is an apocalyptic number.

It is an amenable number.

19519928605 is a deficient number, since it is larger than the sum of its proper divisors (3903985727).

19519928605 is an equidigital number, since it uses as much as digits as its factorization.

19519928605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3903985726.

The product of its (nonzero) digits is 1749600, while the sum is 55.

The spelling of 19519928605 in words is "nineteen billion, five hundred nineteen million, nine hundred twenty-eight thousand, six hundred five".