19729577406 has 64 divisors (see below), whose sum is σ = 49252686336. Its totient is φ = 5118643200.

The previous prime is 19729577401. The next prime is 19729577419. The reversal of 19729577406 is 60477592791.

It is a happy number.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19729577401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 382786 + ... + 431258.

It is an arithmetic number, because the mean of its divisors is an integer number (769573224).

Almost surely, 2^19729577406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19729577406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24626343168).

19729577406 is an abundant number, since it is smaller than the sum of its proper divisors (29523108930).

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

19729577406 is a wasteful number, since it uses less digits than its factorization.

19729577406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49377.

The product of its (nonzero) digits is 6667920, while the sum is 57.

The spelling of 19729577406 in words is "nineteen billion, seven hundred twenty-nine million, five hundred seventy-seven thousand, four hundred six".