19539439872 has 288 divisors, whose sum is σ = 59338137600. Its totient is φ = 5671649280.

The previous prime is 19539439859. The next prime is 19539439879. The reversal of 19539439872 is 27893493591.

It is not an unprimeable number, because it can be changed into a prime (19539439879) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9307879 + ... + 9309977.

It is an arithmetic number, because the mean of its divisors is an integer number (206035200).

Almost surely, 2^19539439872 is an apocalyptic number.

19539439872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19539439872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29669068800).

19539439872 is an abundant number, since it is smaller than the sum of its proper divisors (39798697728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19539439872 is a wasteful number, since it uses less digits than its factorization.

19539439872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2189 (or 2175 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 60.

The spelling of 19539439872 in words is "nineteen billion, five hundred thirty-nine million, four hundred thirty-nine thousand, eight hundred seventy-two".