19385990405 has 4 divisors (see below), whose sum is σ = 23263188492. Its totient is φ = 15508792320.

The previous prime is 19385990401. The next prime is 19385990411. The reversal of 19385990405 is 50409958391.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50409958391 = 13 ⋅3877689107.

It can be written as a sum of positive squares in 2 ways, for example, as 2193798244 + 17192192161 = 46838^2 + 131119^2 .

It is not a de Polignac number, because 19385990405 - 2² = 19385990401 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19385990401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1938599036 + ... + 1938599045.

It is an arithmetic number, because the mean of its divisors is an integer number (5815797123).

Almost surely, 2^19385990405 is an apocalyptic number.

It is an amenable number.

19385990405 is a deficient number, since it is larger than the sum of its proper divisors (3877198087).

19385990405 is an equidigital number, since it uses as much as digits as its factorization.

19385990405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3877198086.

The product of its (nonzero) digits is 1749600, while the sum is 53.

The spelling of 19385990405 in words is "nineteen billion, three hundred eighty-five million, nine hundred ninety thousand, four hundred five".