19239631849 has 9 divisors (see below), whose sum is σ = 19930111383.
Its totient is φ = 18572312472.
The previous prime is 19239631847. The next prime is 19239631891. The reversal of 19239631849 is 94813693291.
It is a happy number.
The square root of 19239631849 is 138707.
It is a perfect power (a square), and thus also a powerful number.
It can be written as a sum of positive squares in only one way, i.e., 10088796249 + 9150835600 = 100443^2 + 95660^2
It is not a de Polignac number, because 19239631849 - 21 = 19239631847 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 19239631849.
It is not an unprimeable number, because it can be changed into a prime (19239631847) by changing a digit.
It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4020112 + ... + 4024894.
Almost surely, 219239631849 is an apocalyptic number.
19239631849 is the 138707-th square number.
19239631849 is the 69354-th centered octagonal number.
It is an amenable number.
19239631849 is a deficient number, since it is larger than the sum of its proper divisors (690479534).
19239631849 is an frugal number, since it uses more digits than its factorization.
19239631849 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 9624 (or 4812 counting only the distinct ones).
The product of its digits is 2519424, while the sum is 55.
The spelling of 19239631849 in words is "nineteen billion, two hundred thirty-nine million, six hundred thirty-one thousand, eight hundred forty-nine".