19738049509 has 4 divisors (see below), whose sum is σ = 20776894240. Its totient is φ = 18699204780.

The previous prime is 19738049497. The next prime is 19738049521. The reversal of 19738049509 is 90594083791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90594083791 = 11807 ⋅7672913.

It is an interprime number because it is at equal distance from previous prime (19738049497) and next prime (19738049521).

It is a cyclic number.

It is not a de Polignac number, because 19738049509 - 2⁵ = 19738049477 is a prime.

It is a super-3 number, since 3×19738049509³ (a number of 32 digits) contains 333 as substring.

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 19738049509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19738049599) 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, 519422337 + ... + 519422374.

It is an arithmetic number, because the mean of its divisors is an integer number (5194223560).

Almost surely, 2^19738049509 is an apocalyptic number.

19738049509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19738049509 is a deficient number, since it is larger than the sum of its proper divisors (1038844731).

19738049509 is a wasteful number, since it uses less digits than its factorization.

19738049509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038844730.

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

The spelling of 19738049509 in words is "nineteen billion, seven hundred thirty-eight million, forty-nine thousand, five hundred nine".