19647477985 has 8 divisors (see below), whose sum is σ = 23810409576. Its totient is φ = 15562358400.

The previous prime is 19647477973. The next prime is 19647478033. The reversal of 19647477985 is 58977474691.

It can be written as a sum of positive squares in 4 ways, for example, as 11724341841 + 7923136144 = 108279^2 + 89012^2 .

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

It is not a de Polignac number, because 19647477985 - 2¹¹ = 19647475937 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 19647477985.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19452444 + ... + 19453453.

It is an arithmetic number, because the mean of its divisors is an integer number (2976301197).

Almost surely, 2^19647477985 is an apocalyptic number.

It is an amenable number.

19647477985 is a deficient number, since it is larger than the sum of its proper divisors (4162931591).

19647477985 is a wasteful number, since it uses less digits than its factorization.

19647477985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38906003.

The product of its digits is 106686720, while the sum is 67.

The spelling of 19647477985 in words is "nineteen billion, six hundred forty-seven million, four hundred seventy-seven thousand, nine hundred eighty-five".