19947978752 has 144 divisors (see below), whose sum is σ = 44920824480. Its totient is φ = 8789164032.

The previous prime is 19947978751. The next prime is 19947978781. The reversal of 19947978752 is 25787974991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19947978751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39190274 + ... + 39190782.

It is an arithmetic number, because the mean of its divisors is an integer number (311950170).

Almost surely, 2^19947978752 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19947978752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22460412240).

19947978752 is an abundant number, since it is smaller than the sum of its proper divisors (24972845728).

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

19947978752 is an frugal number, since it uses more digits than its factorization.

19947978752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 547 counting only the distinct ones).

The product of its digits is 80015040, while the sum is 68.

The spelling of 19947978752 in words is "nineteen billion, nine hundred forty-seven million, nine hundred seventy-eight thousand, seven hundred fifty-two".