19894739328 has 192 divisors, whose sum is σ = 60783203520. Its totient is φ = 6224363520.

The previous prime is 19894739323. The next prime is 19894739363. The reversal of 19894739328 is 82393749891.

19894739328 is a `hidden beast` number, since 198 + 94 + 7 + 39 + 328 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19894739321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8439526 + ... + 8441882.

It is an arithmetic number, because the mean of its divisors is an integer number (316579185).

Almost surely, 2^19894739328 is an apocalyptic number.

19894739328 is a gapful number since it is divisible by the number (18) 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 19894739328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30391601760).

19894739328 is an abundant number, since it is smaller than the sum of its proper divisors (40888464192).

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

19894739328 is a wasteful number, since it uses less digits than its factorization.

19894739328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2825 (or 2810 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 63.

The spelling of 19894739328 in words is "nineteen billion, eight hundred ninety-four million, seven hundred thirty-nine thousand, three hundred twenty-eight".