19475039809 has 9 divisors (see below), whose sum is σ = 20690538537. Its totient is φ = 18327216384.

The previous prime is 19475039807. The next prime is 19475039851. The reversal of 19475039809 is 90893057491.

The square root of 19475039809 is 139553.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 959450625 + 18515589184 = 30975^2 + 136072^2 .

It is not a de Polignac number, because 19475039809 - 2¹ = 19475039807 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 19475039809.

It is not an unprimeable number, because it can be changed into a prime (19475039807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2368297 + ... + 2376505.

Almost surely, 2^19475039809 is an apocalyptic number.

19475039809 is the 139553-rd square number.

19475039809 is the 69777-th centered octagonal number.

It is an amenable number.

19475039809 is a deficient number, since it is larger than the sum of its proper divisors (1215498728).

19475039809 is an frugal number, since it uses more digits than its factorization.

19475039809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16452 (or 8226 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 55.

The spelling of 19475039809 in words is "nineteen billion, four hundred seventy-five million, thirty-nine thousand, eight hundred nine".